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Object selectivity in dorsal visual stream.Subramanian, Janani 14 September 2011 (has links)
We scan the visual world by making rapid eye movements (saccades) and serially focusing on objects of interest. Despite abrupt retinal image shifts, we see the world as stable. Remapping contributes to visual stability by updating the internal image with every saccade. Neurons in macaque lateral intraparietal cortex (LIP) and other brain areas update information about salient objects around the time of a saccade. Information about salient objects is transferred from neurons that currently encode their screen locations to other neurons that will encode their locations after the saccade. The depth of information transfer remains to be thoroughly investigated. Area LIP, as part of the dorsal visual stream is regarded as a spatially selective area. Yet there has been increasing evidence that LIP neurons also encode object features.
We sought to determine whether LIP remaps shape information. Such insight is required for understanding what information is retained from each glance and how the visual percept is built (transsaccadic perception). First, we presented shapes in the future location of the receptive field around the time of the saccade and tested for shape selectivity during remapping. Second, we presented the same shapes within the receptive field and tested for shape selectivity in the fixation task. Finally, we compared selectivity in the two tasks. We found that LIP neurons automatically encode and remap shape information. Selectivity in the two tasks was comparable. Our results provide critical evidence for the idea that remapping may be a mechanism for transsaccadic perception of features.
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Estudo da atividade antifúngica e dos mecanismos de ação do peptídeo Ctn[15-34], um fragmento C-terminal da crotalicidina, derivado de uma catelicidina expressa nas glândulas de veneno de cascavéis / Study of the antifungal activity and mechanisms of action of the Ctn peptide [15-34], a C-terminal fragment of crotalicidin, derived from a cathelicidin expressed in rattlesnake venom glandsTargino, Carolina Sidrim de Paula Cavalcante 27 April 2017 (has links)
TARGINO, C. S. P. C. Estudo da atividade antifúngica e dos mecanismos de ação do peptídeo Ctn[15-34], um
fragmento c- terminal da Crotalicidina, derivado de uma catelicidina expressa nas glândulas de veneno de cascavéis. 2017. 131 f. Tese (Doutorado em Ciências Farmacêuticas) - Faculdade de Farmácia, Odontologia e Enfermagem, Universidade Federal do Ceará, Fortaleza, 2017. / Submitted by ciências farmacêuticas pgcf (pgcf.ufc@gmail.com) on 2017-06-12T13:41:28Z
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Previous issue date: 2017-04-27 / Crotalicidin (Ctn), a 34-residue cathelicidin from a South American rattlesnake, and its fragment (Ctn[15–34]) have shown anti-infective and cytotoxic activities against Gramnegative bacteria and certain tumor lines, respectively. The extent of such effects has been related to physicochemical characteristics such as helicity and hydrophobicity. We now report the anti-fungal activity of Ctn and its fragments (Ctn[1–14]) and (Ctn[15–34]) And characterize the possible mechanisms of action of peptides against Candida albicans.MIC determination and luminescent cell viability assays were used to evaluate the anti-infective activity of Ctn and its fragments (Ctn[1–14]) and (Ctn[15–34]) as anti-fungal agents against opportunistic yeast and dermatophytes. Cytotoxicity towards healthy eukaryotic cells was assessed in vitro with healthy human kidney-2 (HK-2) cells and erythrocytes. Fragments Ctn[1–14] and Ctn[15–34] lost activity against dermatophytes, but became more active against pathogenic yeasts, including several Candida species and Cryptococcus laurentii, with MICs as low as 5 μM. Interestingly, the two peptide fragments were less cytotoxic to healthy HK-2 cells and less hemolytic to human erythrocytes than the standard-of-care amphotericin B (AMB).The checkerboard technique was performed to estimate the effects of combining either one of the peptides with AMB against C. albicans strains, and it was the synergy between Ctn peptides and AMB, with consequent reduction in MICs of both drug and peptides. In general, the Ctn[15-34] presented the smallest MICs against the different Candida species, and low cytotoxicity against eukaryotic cells. To characterize the anti- Candida activity of Ctn[15-34] were performed the phospholipase activity assay, time killing assay, and flow cytometry techniques.The plasmatic membrane damage was roughly estimated based on the amount of product generated by phospholipase activity after treatment of 4N3OBA lipid (substrate) with Ctn[15-34]; At 10 μM a big increase in phospholipase activity could be noticed compared to non-treated and treated lipids at 5μM. Analysis of the time killing assays of cells treated with Ctn [15-34] and AMB, showed that they did not reduce the number of CFUs in the same fashion, which suggested that Ctn[15-34] and AMB could have different mechanisms of action against C.albicans. Ctn[15-34] alone promoted cell membrane disruption, like other AMPs, in yeasts. Moreover, the C. albicans cell death pathway detected after the peptide treatment was necrosis, which further confirmed cell membrane damage capacity by Ctn[15-34].Together, Ctn and its fragments are promising for the treatment of fungal diseases, and the Ctn [15-34] is a most valuable candidate for further 12 development as an antifungal therapeutic peptide lead, particularly against yeast infections where it could be usedfully applied either alone or in combination with a standard antibiotic such as AMB. / A crotalicidina (Ctn), uma catelicidina de 34-resíduos isolada de cascavel da América do Sul, e o seu fragmento (Ctn[15-34]) demonstraram previamente atividades antimicrobiana contra bactérias Gram negativas e citotóxica contra células tumorais. A extensão de tais efeitos tem sido relacionada com suas características físico-químicas, como a forma helicoidal e hidrofobicidade. O presente trabalho teve o objetivo geral de avaliar a atividade antifúngica do Ctn e seus fragmentos (Ctn[1-14] e Ctn[15-34]) e caracterizar os possíveis mecanismos de ação dos peptídeos contra Candida albicans. Determinação de Concentração inibitória mínima (CIM) e ensaios de viabilidade celular por ensaios de luminescência foram utilizados para avaliar a ação do Ctn e seus fragmentos (Ctn[1-14] e Ctn[15-34]) como agentes antifúngicos contra cepas clínicas de leveduras oportunistas e dermatófitos. A citotoxicidade em relação a células eucarióticas foi avaliada in vitro com células renais da linhagem HK-2 e eritrócitos. Ctn foi o peptídeo mais ativo contra dermatófitos e também o mais tóxico para células eucarióticas saudáveis. Os fragmentos Ctn[1-14] e Ctn [15-34] não demonstraram atividade contra dermatófitos, mas foram ativos contra leveduras patogênicas, incluindo várias espécies de Candida sp. e Cryptococcus laurentii, com CIMs de até 5μm. É interessante notar que os dois fragmentos peptídicos foram menos citotóxicos para as células HK-2 e menos hemolíticos para os eritrócitos humanos do que a Anfotericina B (ANF). A técnica checkerboard foi realizada para estimar os efeitos da combinação dos peptídeos com ANF frente a cepas de C. albicans. Foi observado o efeito sinérgico entre as crotalicidinas e a ANF, com a consequente redução nas CIM de ambos, fármaco e peptídeos. De modo geral, o fragmento Ctn[15-34] apresentou as menores CIMs contra as diferentes espécies de Candida, e baixa citotoxicidade contra células eucariotas. Para caracterizar a atividade anti-Candida do Ctn[15-34] foram realizados ensaios para determinar atividade fosfolipásica, a curva do tempo de morte, e técnicas de citometria de fluxo. O dano à membrana plasmática foi estimado com base na quantidade de produto gerada pela atividade fosfolipásica após tratamento do lípido 4N3OBA (substrato) com Ctn[15-34]; a 10 μM pode ser observado um grande aumento na atividade fosfolipásica em comparação com os lipídeos não tratados, e tratados com 5 μM. A análise das curvas de tempo de morte das células tratadas com Ctn[15-34] e AMB, mostrou que eles não reduziram o número de UFCs da mesma forma, sugerindo que Ctn[15-34] e AMB poderiam ter diferentes mecanismos de ação contra C .albicans. Ctn[15-34] promoveu rompimento da membrana celular, assim como outros peptídeos 10 antimicrobianos (PAMs), em leveduras. Além disso, a via de morte celular da C. albicans detectada por citometria após o tratamento com peptídeo foi a necrose, o que confirmou ainda mais a capacidade de dano da membrana celular por Ctn[15-34]. Juntos, Ctn e seus fragmentos são promissores para o tratamento de doenças fúngicas, e o Ctn[15-34] é um candidato muito valioso para o futuro desenvolvimento de um peptídeo antifúngico, que pode ser aplicado sozinho ou em combinação com um antibiótico padrão como a AMB
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Um enfoque imunológico sobre infecção viral em Litopenaeus vannamei coletados em fazenda de cultivo do Nordeste do BrasilGirão, Patricia Raquel Nogueira Vieira January 2013 (has links)
GIRÃO, P. R. N. V. Um enfoque imunológico sobre infecção viral em Litopenaeus vannamei coletados em fazenda de cultivo do Nordeste do Brasil. 2013. 92 f. Dissertação (Mestrado em Ciências Marinhas Tropicais) - Instituto de Ciências do Mar, Universidade Federal do Ceará, Fortaleza, 2013. / Submitted by Geovane Uchoa (geovane@ufc.br) on 2016-04-25T12:45:57Z
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Previous issue date: 2013 / The shrimp farming has become an important aquaculture industry in the world. Brazil is becoming a leading global producer of shrimp Litopenaeus vannamei. However, outbreaks of viral diseases are affecting the aquaculture industry worldwide, causing significant economic losses. Among the viral agents that affect the marine shrimp Infectious hypodermal and hematopoietic necrosis virus (IHHNV) and infectious myonecrosis virus (IMNV) are prevalent epizootic viral agents in Brazil. Within this context, this study aimed to analyze samples of virus-infected shrimp collected from farms in northeastern Brazil, as well as analyzing the expression levels of molecules of immunity during infection of animals. After a period of unusual rains in a routine monitoring program for the diagnosis of diseases were collected gills of juvenile shrimp with signs of viral disease. For the diagnosis of infection were employed molecular techniques such as conventional PCR, reverse transcription coupled with PCR (RT-PCR) and quantitative PCR (qPCR). Through a combination of different molecular techniques has shown that most of shrimp patients were co-infected with both viruses, IHHNV and IMNV. This study was the first to demonstrate the occurrence of a natural co-infection, caused by IHHNV and IMNV in penaeid shrimp cultured in northeastern Brazil. The reciprocal values for viral load may suggest that competition is occurring between the two viruses to infect the host. To understand how the key molecules of innate immunity respond to this double infection, the level of HSP-70, crustin, peneidinas-3a and C-type lectin-br1 were assessed by quantitative PCR. In tests using linear correlation, HSP-70 expression is regulated by the presented IHHNV in doubly infected shrimp gills, however, transcripts of other genes analyzed showed no statistically significant regulated expression. These results suggest that HSP-70 may be a differential modulator co-infection viral in shrimp, L. vannamei. / O cultivo de camarão tornou-se uma importante indústria na aquicultura mundial. O Brasil está se tornando um dos principais produtores mundiais de camarão Litopenaeus vannamei. Entretanto, surtos de doenças virais estão afetando o setor aquícola em todo o mundo, causando perdas econômicas significativas. Entre os agentes virais que afetam os camarões marinhos, o vírus da necrose infecciosa hipodermal e hematopoiética (IHHNV) e o vírus da mionecrose infecciosa (IMNV) são os vírus epizoóticos mais prevalentes no Brasil. Dentro desse contexto, este trabalho teve como objetivo analisar amostras de camarão infectado por vírus coletadas de fazendas de cultivo no Nordeste do Brasil, bem como analisar os níveis de expressão de moléculas da imunidade dos animais durante a infecção. Após um período incomum de chuvas, em um programa de monitoramento de rotina para o diagnóstico de doenças, foram coletadas brânquias de camarões juvenis com sinais de doença viral. Para o diagnóstico da infecção foram utilizandas técnicas moleculares como PCR convencional, a transcrição reversa acoplada com PCR (RT-PCR) e PCR quantitativo (qPCR). Através da combinação das diferentes técnicas moleculares foi demonstrado que a maioria dos camarões doentes estavam co-infectados com ambos os vírus, IHHNV e IMNV. Este estudo foi o primeiro a demonstrar a ocorrência de uma co-infecção natural, causada por IHHNV e IMNV, em camarões peneídeos cultivados no nordeste do Brasil. Os valores recíprocos para carga viral sugeriram que pode está ocorrendo uma competição entre os dois vírus para infectar o hospedeiro. Para compreender como as moléculas-chave da imunidade inata respondem a esta dupla infecção, os níveis de HSP-70, crustinas, peneidinas-3a e lectina br-1 do tipo-C, foram avaliados por PCR quantitativo. Em testes de correlação linear, a HSP-70 apresentou a expressão regulada por IHHNV em brânquias de camarão duplamente infectado; no entanto, as transcrições dos demais genes analisados não apresentaram expressão regulada estatisticamente significativa. Esses resultados indicam que a HSP-70 pode ser um modulador diferencial de co-infecção viral no camarão, L. vannamei.
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Studies On Batch And Continuous Sonochemical ReactorsGanesh, N 11 1900 (has links) (PDF)
No description available.
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Can Religion Help? Using John Howard Yoder and Mohandas Gandhi to Conceptualize New Approaches to Intractable Social and Political Problems such as Violence and WarKeeter, Gregory T. 12 June 2006 (has links)
Religious Studies is making possible a scholarly study of many aspects of human religious traditions and practices, but the field has yet to articulate fully the ability of such study to affect the creation of new approaches to intractable social and political problems. Many of these problems have as their basis religious justifications, yet the rigor of academic thought has only barely begun to clarify the underlying religious reasoning. Through this essay I intend to provide clarity to some of the underlying religious justifications for war and violence by examining the religious writings of two widely recognized theologians that firmly oppose war and violence, John Howard Yoder and Mohandas Gandhi. The result is an examination on the utility of using religious ideas as sources of insights and strategies for addressing social and political issues such as war and violence.
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The challenges experienced by school governing bodies in the implementation of the code of conduct for learners : a case study of two secondary schools in the Mafukuzela-Gandhi circuit.Pillay, Thegen. January 2012 (has links)
This study investigated the challenges experienced by school governing bodies in the implementation of the code of conduct for learners. A case study was conducted in two secondary schools from the Mafukuzela-Gandhi circuit in the Pinetown Region of KwaZulu-Natal. The aims of this study was to find out how SGBs implement the code of conduct for learners at their schools; what challenges SGBs experienced in the implementation of the code of conduct for learners and why SGBs are regarded as the most important structure to implement the code of conduct for learners. This qualitative study was set in the interpretivist paradigm. The research tools compromises of semi-structured interviews, documents analysis and observations. The two theories which underpin this study are democratic school governance theory and discipline theory. A review of international and local literature around issues of discipline revealed that some of the challenges of learner discipline encountered by South African Schools were being experienced world-wide. The findings of this research were a revelation to me. I had the privilege of experiencing first-hand what secondary schools educators, managers and parents encountered and dealt with on a daily basis. It is evident that learner misdemeanor is on the increase; educator’s teaching time is being consumed in dealing with disciplinary issues; educators are becoming frustrated and demoralised; the tribunal hearing are not regarded as an effective structure by learners; parental involvement is lacking and parents seem to have abdicated the responsibility of their children’s behaviour and education to the school and SGB parents play a limited role in the activities of the school due to their incapacity and lack of empowerment.
Some of the recommendations based on the findings are that schools must involve all stakeholders in the formulation of the policy. The contents and procedures outlined in the policy must be communicated to all stakeholders and there must be consistency in its application. SGBs must formulate innovative strategies to engage parents to actively participate in the activities of the school. The Department of Education must fulfill its obligation to capacitate parent and other stakeholders on the SGB. An empowered SGB will make a greater contribution to the governance of schools. / Thesis (M.Ed.) - University of KwaZulu-Natal, Edgewood, 2012.
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Short-range magnon excitation and spontaneous exchange bias phenomenon in NiO nanoparticles / 奈米氧化鎳之短程磁振子激發與自發磁 交換異性研究Ashish Chhaganlal Gandhi, 甘地亞旭 January 2015 (has links)
博士 / 國立東華大學 / 物理學系 / 103 / The possibility of size dependency of the optical and magnetic properties of nanostructured 3d transition metal oxides has opened up the path for extensive research activities in recent years. In this thesis, we report a unique synthesis technique and a comprehensive step wise characterization process to describe the effect of finite size and nickel vacancies on the optical and magnetic properties of NiO nanoparticles with size varying from 16.6(7) to 54(6) nm. The XRD study reveals short-range crystallinity. The finite size effect with nickel vacancies resulted in the formation of uncompensated antiferromagnetic nanoparticles with frustrated and disordered spins at the surface. Due to high nickel vacancies, the superexchange mechanism relaxes and shows short-range magnon excitation in small size nanoparticles at room temperature. A critical size of
~11 nm was predicted below which, due to enhanced nickel vacancies, magnon excitation disappears. Magnetic measurement unveil the existence of ferromagnetic and antiferromagnetic component in small size NiO nanoparticles. Relaxation dynamics
reveal that system of small size particles is poly-dispersed/densely packed (16.6(7) nm, n = 0.93) resulting in interparticle interactions because of ferromagnetic component. A
spontaneous exchange bias (SEB) phenomenon was observed in small sized interacting nanoparticles, which disappear in large sized particles due to reduced FM component. The observed SEB effect is attributed to the intercoupling of spins at the interface of
short-range ordered clusters of spins which behave like FM to the uncompensated AFM.
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Compliant load-bearing skins and structures for morphing aircraft applicationsOlympio, Kingnidé Raymond, Gandhi, Farhan S., January 2009 (has links)
Thesis (Ph.D.)--Pennsylvania State University, 2009. / Mode of access: World Wide Web. Thesis advisor: Farhan Gandhi.
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Further investigations on primary helicopter control using trailing edge flapsDuling, Christopher T. Gandhi, Farhan S., January 2009 (has links)
Thesis (M.S.)--Pennsylvania State University, 2009. / Thesis advisor: Farhan S. Gandhi.
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Fuzzy Forecasting Based on Two-Factors High-Order Fuzzy-Trend Logical Relationship Groups and Particle Swarm Optimization Techniques / 根據兩因子高階模糊趨勢邏輯關係群及粒子群最佳化技術以作模糊預測之新方法Gandhi Maruli Tua Manalu, 王感天 January 2011 (has links)
碩士 / 國立臺灣科技大學 / 資訊工程系 / 99 / Fuzzy time series have been widely used in solving forecasting problem, such as the enrollments forecasting, the temperature forecasting, the stock index forecasting, the exchange rates forecasting, …, etc. Particle swarm optimization is a swarm-based optimization method that can find a near optimal solution for any kind of optimization problems. Therefore, if we can use it appropriately to determine the optimal proportion of the data in the current dates in calculating the data in the next date, we can get a nearly-optimal solution. In this thesis, we present a new method for fuzzy forecasting based on two-factors high-order fuzzy-trend logical relationship groups and particle swarm optimization techniques. First, we fuzzify the historical training data of the main factor and the secondary factor, respectively, to form two-factors high-order fuzzy logical relationships. Then, we group the two-factors high-order fuzzy logical relationships into two-factors high-order fuzzy-trend logical relationship groups. Then, we obtain the optimal weighting vectors for each fuzzy-trend logical relationship group by using particle swarm optimization techniques to perform the forecasting. We also apply the proposed method to forecast the Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX) and the NTD/USD exchange rates. The experimental results show that the proposed method gets higher average forecasting accuracy rates than the existing methods.
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