This study aimed to increase understanding of students' interactions in a physics microcomputer-based laboratory (MBL) specifically designed to be consistent with a constructivist theory of learning. The study was motivated by a perceived need to understand better how the materials and strategies support or constrain students construction of understanding. The teacher-researcher conducted the study with two of his Year 11 physics classes, comprising 15 students studying thermal physics and 29 students studying kinematics. Dyads of students worked at tasks using a predict-observe-explain (POE) format as part of the normal class program. Data included video and audio recordings during four 70-minute sessions for each class, students' written notes, semi-structured student interviews, and the teacher's reflections on each session. The study describes the actors and network relationships during task activities. An analysis of students' discourse identified features common to both domains of physics, while the findings about studentdisplay- teacher interactions are presented as a series of eight assertions. Finally, the researcher's interpretation of learning in an MBL leads to recommendations for teaching practice.

Mannose binding lectin (MBL) belongs to the collectin family of soluble pattern recognition molecules that elicit diverse biologic activities. Via multiple carbohydrate-recognition domains (CRD), MBL binds to mannose and N-acetyl-glucosamine oligosaccharides present on the surface of bacteria, fungi and yeast. Following pathogen recognition, MBL activates the complement system via MBL associated serine proteases in a manner independent of antibody and C1 complex. Deficiency in function and level of MBL is found in 25% of otherwise apparently healthy individuals, representing the most prevalent innate immune deficiency. MBL deficiency is a risk factor for the development of infections in humans and mice. The role of MBL as a modulator of infection is complex. MBL deficiency may influence proinflammatory cytokine production, expression of leukocyte adhesion molecules, or vascular damage, during the course of infection. Given that dendritic cells (DC) are antigen presenting cells (APC) with potent capacity to respond to microbial stimulation, I hypothesized that MBL deficiency may be reflected in DC functions associated with microbial stimulation. Initially, I investigated the association of MBL with human immune cells and demonstrated that in both MBL-Sufficient (MBL-S) and MBL-Deficient (MBL-D) individuals, MBL was particularly associated with monocytes. RT-PCR analysis demonstrated MBL was not transcribed by monocytes or other immune cells investigated (T, B, and NK cells, CD11c+DC, immature monocyte derived DC [MoDC], LPS matured MoDC, and granulocytes), suggesting MBL association with the cell surface may be via an adapter or co-receptor. Magnetically separated monocytes but not MoDC bound exogenous purified human plasma MBL (hpMBL). Addition of hpMBL (5 -15 µg/mL) did not induce MoDC activation, and MBL added together with lipopolysaccharide (LPS) did not induce MoDC activation above the level induced by LPS only. In the second part of this study, I used the particulate MBL ligand zymosan (Zy) as a pathogenic stimulus in a whole blood model to gain a greater understanding of the consequences of MBL deficiency. I compared surface phenotype, inflammatory cytokine production and antigen presenting capacity of blood myeloid (M)DC of MBL-D and MBL-S individuals following stimulation with Zy and MBL opsonised Zy (MBL-Zy). Blood MDC in MBL-D individuals, unlike their counterpart in MBL-S individuals, displayed unique functional characteristics, including higher production of proinflammatory cytokines IL-6 and TNF-, but poor capacity for allo-T cell effector cell induction. It appeared that stimulation with MBL-Zy reduced elevated production of IL-6 but not TNF- by blood MDC in MBL-D individuals. In the third part, expression microarray analysis was utilised to provide broad information on the genes and potential signalling pathways involved in the MDC responses in MBL-D and MBL-S individuals following stimulation with Zy and MBL-Zy. MBL-S individuals demonstrated greater capacity to induce T cell and NK cell signalling pathways than MBL-D individuals. Further, MBL acted as a regulator of important inflammatory molecules, namely T-cell receptor zeta (CD247), IFN-γ and perforin 1. The data presented in this study provides novel information on blood MDC function in MBL-S and MBL-D individuals in response to pathogen stimulation, and provided insight into mechanisms involved in the increased frequency of infection observed in MBL-D individuals.

The complement system is a part of the innate immunity. Its function is to eliminate pathogens, by proteins interacting directly with pathogen surfaces and promoting a pro-inflammatory and anti-microbial environment. Related to the lectin pathway of the complement system are ten known proteins, with component properties and disease association still unclear. The aim of this study was to evaluate the instrument WES for the detection of seven proteins associated to the lectin pathway. The novel instrument introduces an automated technique based on capillary electrophoresis and immunoblotting. Trials were performed on donor plasma using instrument associated kits. For the evaluation, these kits were combined with assorted primary and secondary antibodies from several species, as well as antibodies in biotinylated form. The high protein content of plasma caused many artefacts, affecting separation and displaying unspecific binding of both primary and secondary antibodies. Biotinylated antibodies coupled with the kit streptavidin-horseradish peroxidase showed the best results for further trials. Several issues remain to be solved in the optimization, including determining the unspecificity of biotinylated primary antibodies, best antibody concentrations and optimal sample preparation and dilution.

La thèse vise à apprécier les effets de la mise en oeuvre d'un dispositif d'ExAO comparativement à d'autres modalités plus classiques de TP (laboratoire traditionnel et exposé d'expériences). L'apprentissage concerné est celui du concept de réaction chimique par des élèves de 5ème au Liban. Les élèves soumis aux trois modalités pédagogiques ont été confrontés à deux reprises à une épreuve commune de connaissances (prétest et post-test). Les données analysées portent de plus sur les comptes rendus d'expérience réalisés par les élèves des trois groupes. Les résultats attestent d'un effet positif plus important de la modalité de travail par ExAO. Du point de vue quantitatif les élèves de ce groupe ont nettement plus progressé que les autres eu égard à la plupart des dimensions de l'apprentissage concerné. D'un point de vue qualitatif, il s'avère en outre que ces élèves ont fait preuve d'un meilleur niveau de compréhension du contenu du TP réalisé. / The thesis aims at assessing the effects of the implementation of MBL compared with two other classic lab work methods (the presentation of lab work and lab work displaying). The course given to students in grade 7 in Lebanon focuses on the concept of chemical reaction. The students in all three groups sat for both a pre-test and a post-test of knowledge, created specifically for this study. The analyzed data cover also the reports made by students of all three groups.The results are consistent with a positive effect of the modality of MBL work. From a quantitative point of view, the students in this group are significantly more advanced than others in relation to the most relevant dimensions of learning. From a qualitative point of view, it also turns out that these students have demonstrated a greater level of understanding of the content of lab work achieved.

Som huvudregel är en huvudman ansvarig för skada vållad av arbetstagare denne har i sin tjänst, ett så kallat principalansvar. I undantagsfall är även en huvudman ansvarig för skada vållad av den som formellt sett inte är en arbetstagare. I denna uppsats fastslås att vissa typer av gig-arbete omfattas av ett principalansvar. Gig-arbetare är en relativt ny arbetsrättslig term, som ännu inte kommit att behandlas i svensk rätt. I denna uppsats avser vi att konkretisera en skadeståndsrättslig utgångspunkt för gig-arbete, närmare bestämt i vilken mån gig-arbetare omfattas av ett principalansvar. Gig-arbetare omfattas i regel inte av ett anställningsavtal, gig-företagen tenderar i stället att klassificera de arbetspresterande som självständiga uppdragstagare. Huruvida en sådan klassificeringen av en arbetspresterare är legitim eller inte är av central vikt vid fastställandet av den arbetspresterandes rättigheter. För att klarlägga principalansvarets omfattning redogörs således först för de arbetspresterandesarbetsrättsliga situation. Arbetsrättens lagstiftning tillhandhåller inga tydliga definitioner av vad som utgör en arbetstagare, vilket innebär att svaret på frågan måste sökas på annat håll i rättskällehierarkin. I uppsatsen redogörs även för grundläggande skadeståndsrätt, med fokus på principalansvaret och dess omfattning, samt fenomenet gig-ekonomi och parterna aktiva däri. Den presenterade informationen ställs därefter i relation till arbete på gig-ekonomiska premisser. I uppsatsens slutsats konstateras att vissa typer av gig-arbete ska omfattas av ett principalansvar. Eftersom gig-ekonomin är mångfacetterad och föränderlig har det emellertid inte varit möjligt att fastslå principalansvarets exakta omfattning i sammanhanget. För att nå en slutsats i ett specifikt fall, måste en bedömning göras utifrån de unika omständigheterna som råder i just det fallet. Uppsatsens slutsats ska således förstås som en sorts grundsats eller huvudregel.

Many of the experiments available for working with probeware are aimed at the grammar school level. However, with the proliferation of more sophisticated sensors, there is an opportunity to develop experiments for chemistry-oriented vocational schools (specialization Applied Chemistry). These experiments would benefit from the advantages of the vocational school - more time available in the laboratory, better instrumentation, and a wider range of learning topics allowing for more challenging experiments. However, these would also work as advanced experiments for grammar school level chemistry education. The theoretical part discusses probeware, its use for teaching chemistry, the range of different available sensors and their advantages and disadvantages, as well as sources of available experiments, their categorization and comparison with the Framework Education Programme education topics. This thesis introduces a set of 5 different, fully developed and laboratory-validated experiments selected in accordance with the requirements of the Framework Education Programme and School Education Programme for chemistry-oriented vocational schools. In addition to the write-up of the process of their design and validation in this thesis, the annex provides developed materials for direct use in school labs,...

Made available in DSpace on 2014-06-12T15:07:27Z (GMT). No. of bitstreams: 2 arquivo5620_1.pdf: 8916043 bytes, checksum: 669ed68c15dd8910790b9473691f2d57 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Na ausência de um sistema imune adaptativo propriamente dito, os cnidários se valem de uma série de mecanismos bioquímicos e celulares que coletivamente compreendem sistemas da imunidade inata e são utilizados para o reconhecimento de micro-organismos, tanto parasitas quanto simbiontes. O objetivo do presente trabalho foi investigar se precursores gênicos relacionados a três polipeptídios envolvidos na resposta inata (CTL: lectina do tipo C, MBL: lectina ligante de manose e C3: componente 3 do sistema complemento) seriam expressos em Palythoa caribaeorum. Tendo como base dados moleculares descritos na literatura para os cnidários Nematostella vectensis, Pocillopora damicornis, Acropora millepora e Swiftia exserta, foram utilizadas duas estratégias metodológicas distintas para responder tal proposição: (1) síntese direta de cDNA a partir do RNAm e amplificação dos homólogos por RT-PCR e (2) construção de uma biblioteca de cDNA para propagação e resgate dos precursores completos (full length cDNAs). Ao todo, foram obtidos 11 produtos de RT-PCR (cDNAs amplificados), dos quais um se refere a um segmento similar a um domínio do receptor de imunoglobulinas das células NK (KIR), encontrado em gorilas. A presença de um domínio semelhante a KIR em P. caribaeorum sugeriria a existência de formas alternativas de imunidade antecipatória em cnidários. Tão importante quanto esse achado foi a obtenção de amplicons de CTL. Dessa forma, os níveis de expressão de transcritos de CTL foram comparados entre colônias sadias e doentes (em processo de branqueamento) de P. caribaeorum. Os resultados para o ensaio de expressão diferencial mostraram que a CTL teve uma expressão aumentada entre 63,2 e 65,5% nas colônias branqueadas, o que sugere um possível papel na resposta ao branqueamento, uma vez que essas moléculas participam do processo de reconhecimento celular. Esse resultado pode ser interpretado de duas formas: o aumento na transcrição de CTL após o branqueamento seria uma tentativa de proteção imediata contra patógenos ou estaria envolvido no recrutamento de novos simbiontes. Como um todo, o estudo de moléculas polipeptídicas da imunidade de cnidários é de importância considerável. Não somente fornece dados sobre a ancestralidade e evolução das reações imunes, mas também serve de base para uma série de aplicações de caráter científico e biotecnológico, que vão desde o monitoramento e conservação de espécies marinhas até estudos voltados ao tratamento e cura de doenças que acometem vertebrados superiores

Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-02-11T16:33:10Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_InvestigacaoPolimorfismosExon.pdf: 1535534 bytes, checksum: b86ae2c45bbee081ed98e730a5d77b7f (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-03-31T14:58:32Z (GMT) No. of bitstreams: 2 Dissertacao_InvestigacaoPolimorfismosExon.pdf: 1535534 bytes, checksum: b86ae2c45bbee081ed98e730a5d77b7f (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2014-03-31T14:58:32Z (GMT). No. of bitstreams: 2 Dissertacao_InvestigacaoPolimorfismosExon.pdf: 1535534 bytes, checksum: b86ae2c45bbee081ed98e730a5d77b7f (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2008 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / UNESCO - Organização das Nações Unidas para a Educação, a Ciência e a Cultura / No presente estudo foram investigadas as freqüências das mutações no éxon 1 do gene MBL em um grupo de 128 pacientes com Aids, 116 portadores assintomáticos da infecção pelo HIV-1, 84 mulheres soronegativas profissionais do sexo, com comportamentos de alto risco e 99 indivíduos controles soronegativos, com o objetivo de avaliar a ocorrência de uma possível associação entre os polimorfismos neste gene e a infecção pelo HIV-1. A identificação dos alelos MBL *A, *B, *C e *D foi realizada por meio da reação em cadeia mediada pela polimerase, utilizando sequências de iniciadores específicos e posterior digestão enzimática (RFLP). As análises das frequências alélicas e genotípicas do éxon 1 não mostraram qualquer diferença significativa entre pacientes soropositivos (assintomáticos e Aids) e soronegativos (controle e controle de alto risco) (p>0,05). Não foram observadas associações significativas entre a presença de co-infecções e as variantes alélicas. Entretanto, tuberculose, neurotoxoplasmose, candidíase, neurocriptococose e pneumonia foram as co-infecções com maior prevalência. As associações entre o número de linfócitos TCD4+, a carga viral plasmática e os polimorfismos no éxon 1 do gene MBL nos pacientes com Aids e portadores assintomáticos não foram estatisticamente significante. Desse modo, pode-se sugerir a ausência de associação entre estes polimorfismos e a susceptibilidade à infecção pelo HIV-1, destacando a necessidade de estudos adicionais para determinar se estes polimorfismos apresentam qualquer impacto associado à infecção ou a progressão para a Aids. / The present study investigated the frequency of the mutations in the exon 1 of the MBL gene in a sample of 128 Aids patients, 116 HIV-1 infected asymptomatic individuals, 84 healthy sex worker women with high risk behavior and 99 healthy control individuals, in order to evaluate the occurrence of a possible association between the polymorphisms and HIV-1 infection. The MBL*A, *B, *C and *D alleles identification was performed through a polymerase chain reaction (PCR) followed by restriction endonucleases analyses (RFLP). The analysis of allele and genotype frequencies in the exon 1 of MBL gene did not show any differences between seropositives patients (asymptomatic and Aids individuals) and seronegatives individuals (healthy and high risk controls) (p>0,05). It was not show significant associations between the presences of other related infections and the presence of the alleles variant. However, tuberculosis, toxoplasmosis of the brain, candidosis, meningitis by cryptococcos and pneumonia was the most prevalent co-infections. Associations between the MBL gene polymorphisms and the number of CD4+ T-cells and plasma viral load in the Aids and asymptomatic patients were not statistically significant. Therefore, it has been suggested the absence of association between the polymorphisms and the HIV-1 infection susceptibility, emphasizing the need for further studies to determinate if the present polymorphisms have any impact associated with infection or the progression to Aids.

Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-02-12T14:34:03Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_PolimorfismoRegiaoPromotora.pdf: 865826 bytes, checksum: f861aee9a308caeb0d6d0b408cee5c2d (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-04-10T16:27:56Z (GMT) No. of bitstreams: 2 Dissertacao_PolimorfismoRegiaoPromotora.pdf: 865826 bytes, checksum: f861aee9a308caeb0d6d0b408cee5c2d (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2014-04-10T16:27:56Z (GMT). No. of bitstreams: 2 Dissertacao_PolimorfismoRegiaoPromotora.pdf: 865826 bytes, checksum: f861aee9a308caeb0d6d0b408cee5c2d (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2005 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Um emergente interesse à MBL tem surgido, devido a sua importância no sistema imune inato. Recentes estudos relatam uma influência do polimorfismo na região promotora nas regiões -550 (H/L) e -221 (X/Y) do gene MBL, com a deficiência do sistema imune à determinados patógenos. O objetivo do presente estudo é investigar a associação entre o polimorfismo na região promotora do gene MBL e a infecção pelo HIV-1e a progressão à SIDA/AIDS. No estudo foi feita identificação destes alelos em uma população de 127 pacientes soropositivos para HIV-1 e em 97 indivíduos soronegativos, a partir da técnica de SSP-PCR, utilizando-se seqüências de iniciadores específicos para cada variante. A evolução da infecção nos pacientes soropositivos foi avaliada por meio da contagem de linfócito T CD4⁺ e da carga viral plasmática. As distribuições nas freqüências alélicas e haplotípicas entre os grupos de portadores do HIV-1 e nos controles soronegativos não apresentaram diferenças estatisticamente significantes (p>0,05). Entretanto, pacientes soropostivos portadores do haplótipo HY apresentaram uma maior contagem e uma evolução significativa no número de linfócitos T CD4⁺; e uma menor contagem e maior redução da carga viral plasmática, em relação aos pacientes portadores dos haplótipos LY, LX e HX. Os resultados do presente estudo mostram que a presença de haplótipos relacionados a médios e baixos níveis séricos de MBL podem ter um papel direto na forma como o paciente soropositivo evolui laboratorialmente. Desse modo, conclui-se que a caracterização dos haplótipos da região promotora do gene MBL em portadores da infecção pelo HIV-1 pode ser importante na avaliação do prognóstico de evolução da SIDA/AIDS. / An emergent interest in MBL was appeared in consequence the great importancefor the immune system. At the current study, the prevalence of mutations in -550 (H/L) and -221 (X/Y) MBL gene regions and its impact on the infection by HIV-1 in a population of 128 HIV-1 seropositive and in 97 seronegative patients was evaluated. The alleles identification was performed through SSP-PCR method, using specific primers sequence to each variant. The infection evolution in seropositive patients was evaluated throughout CD4⁺ T-cell counting and plasma viral load. The relation of allele and haplotype frequencies between HIV-1 carriers and seronegative control patients did not show statistically significant differences (p> 0.05). The evaluation of CD4⁺ T-cell mean showed lower levels between seropositive patients who showed LY, LX and HX haplotypes, when compared to seropositive patients showing HY haplotype. These low levels were noticed both at the first (300.8 cells/mL x 405.0 cells/mL) and the second laboratorial evaluation (316.9 cells/mL x 449.9 cells/mL). The plasma viral load mean was higher between seropositive patients who carried LY, LX and HX haplotypes than seropositive patients showing HY haplotype (34,516 copies/mL x 27,482.7 copies/mL). The current study outcomes show that presence of haplotypes related to medium and low MBL serum levels might have a direct role on the way seropositive patient’s laboratorial evolution occurs. Therefore, it was concluded that haplotypes identification in the promoter region of MBL gene in the HIV-1 infection carriers might be relevant in the prognosis evaluation of AIDS progression.

Les collagènes de défense (C1q, MBL, ficolines) sont capables de reconnaître de nombreux motifs à la surface des éléments du non soi ou du soi altéré, via leurs domaines globulaires C-terminaux. Ils peuvent également interagir avec certains récepteurs présents à la surface des cellules humaines ou de pathogènes. Nous nous sommes intéressés dans un premier temps à la calréticuline de Trypanosoma Cruzi (TcCRT), une protéine qui interviendrait dans les mécanismes d'évasion de ce parasite. Dans le but de réaliser des études fonctionnelles et structurales de la TcCRT, nous avons produit différents fragments recombinants. Nous ne sommes cependant pas parvenus à obtenir un échantillon nous permettant d'accomplir nos objectifs, nous conduisant à reporter nos efforts sur l'étude d'un autre récepteur, CR1/CD35. Il a été montré précédemment que CR1/CD35 pouvait interagir avec C1q et la MBL, probablement par ses modules CCP 22-30. Cette interaction pourrait être impliquée dans l'élimination des complexes immuns, la phagocytose ou encore des mécanismes de signalisation cellulaire. A l'aide d'un fragment recombinant comprenant les modules CCP 22-30 de CR1, nous avons confirmé par SPR l'interaction avec C1q et la MBL. Nous avons également montré pour la première fois que CR1 pouvait interagir avec les ficolines L, H et M par ce même domaine. Nos résultats indiquent que cette interaction prendrait majoritairement place dans la région collagène de C1q, de la MBL et de la ficoline L, probablement à proximité du site de fixation des protéases. L'utilisation de fragments tronqués de CR1 CCP 22-30, nous permet de proposer l'hypothèse que les modules CCP 24 et 25 de CR1 seraient le site majoritaire de fixation des collagènes de défense. Ces données ouvrent la voie à des études structurales et fonctionnelles visant à approfondir notre connaissance des interactions CR1 - collagène de défense et de leur rôle physiologique.