Evaluation of digital educational studenttechnology interaction in neonatal nursing

OBJECTIVE To assess the digital educational technology interface Caring for the sensory environment in the neonatal unit: noise, lighting and handling based on ergonomic criteria. METHODS Descriptive study, in which we used the guidelines and ergonomic criteria established by ISO 9241-11 and an online Likert scale instrument to identify problems and interface qualities. The instrument was built based on Ergolist, which follows the criteria of ISO 9141-11. There were 58 undergraduate study participants from the School of Nursing of Ribeirao Preto, University of Sao Paulo, who attended the classes about neonatal nursing content. RESULTS All items were positively evaluated by more than 70% of the sample. CONCLUSION Educational technology is appropriate according to the ergonomic criteria and can be made available for teaching nursing students.

Effect of reducing sensory and environmental stimuli during hospitalized premature infant sleep

OBJECTIVETo compare the total sleep time of premature infant in the presence or absence of reducing sensory and environmental stimuli in the neonatal unit.METHODLongitudinal study in a Neonatal Intermediate Care Unit of a public hospital in Sao Paulo. The sample consisted of 13 premature infants. We used polysomnograph and unstructured observation for data collection. We analyzed 240 and 1200 minutes corresponding to the periods of the presence and absence of environmental management, respectively. Data were compared in proportion to the total sleep time in the two moments proposed by the study.RESULTSThe total sleep time in periods without environmental management was on average 696.4 (± 112.1) minutes and with management 168.5 (± 27.9) minutes, proportionally premature infant slept an average of 70.2% during periods with no intervention and 58.0% without management (p=0.002).CONCLUSIONReducing stimulation and handling of premature infant environment periods was effective to provide greater total sleep time.

Tempo de busca e de manuseio de larvas de Chrysoperla externa (Hagen, 1861) (Neuroptera, Chrysopidae) alimentadas com Uroleucon ambrosiae (Thomas, 1878) (Hemiptera, Aphididae)

Searching and handling time of Chrysoperla externa (Hagen, 1861) (Neuroptera, Chrysopidae) larvae fed on Uroleucon ambrosiae (Thomas, 1878) (Hemiptera, Aphididae). The objective of this research was to determine the searching and handling times of three larval instars of C. externa fed on U. ambrosiae at densities of 30, 40 and 50 per vial, with the feeding of the larvae at the preceding instars being U. ambrosiae nymphs or Sitotroga cerealella (Olivier, 1819) eggs. The larvae were maintained at 25 ± 2 ºC, 70 ± 10% RH and a 14-h photophase. A completely randomized design in a 6 x 3 factorial scheme with 12 replicates was adopted. The shortest searching time was found for the 2nd and 3rd instar larvae of C. externa, and this parameter was variable depending on the feeding given to the larvae previously. The handling time was similar for the 1st, 2nd and 3rd instar larvae. The longest searching time was found at an aphid density of 30, as compared to densities of 40 and 50 prey, with which there were no significant differences. Prey density did not have any influence on handling time.

Stepwise multiple testing as formalized data snooping

It is common in econometric applications that several hypothesis tests arecarried out at the same time. The problem then becomes how to decide whichhypotheses to reject, accounting for the multitude of tests. In this paper,we suggest a stepwise multiple testing procedure which asymptoticallycontrols the familywise error rate at a desired level. Compared to relatedsingle-step methods, our procedure is more powerful in the sense that itoften will reject more false hypotheses. In addition, we advocate the useof studentization when it is feasible. Unlike some stepwise methods, ourmethod implicitly captures the joint dependence structure of the teststatistics, which results in increased ability to detect alternativehypotheses. We prove our method asymptotically controls the familywise errorrate under minimal assumptions. We present our methodology in the context ofcomparing several strategies to a common benchmark and deciding whichstrategies actually beat the benchmark. However, our ideas can easily beextended and/or modied to other contexts, such as making inference for theindividual regression coecients in a multiple regression framework. Somesimulation studies show the improvements of our methods over previous proposals. We also provide an application to a set of real data.

First impressions matter: Signalling as a source of policy dynamics

We first establish that policymakers on the Bank of England's Monetary PolicyCommittee choose lower interest rates with experience. We then reject increasingconfidence in private information or learning about the structure of the macroeconomy as explanations for this shift. Instead, a model in which voters signal theirhawkishness to observers better fits the data. The motivation for signalling is consistent with wanting to control inflation expectations, but not career concerns orpleasing colleagues. There is also no evidence of capture by industry. The papersuggests that policy-motivated reputation building may be important for explainingdynamics in experts' policy choices.

Cerebrospinal fluid in the diagnosis of multiple sclerosis: a consensus report.

The Committee of the European Concerted Action for Multiple Sclerosis (Charcot Foundation) organised five workshops to discuss CSF analytical standards in the diagnosis of multiple sclerosis. This consensus report from 12 European countries summarises the results of those workshops. It is hoped that neurologists will confer with their colleagues in clinical chemistry to arrange the best possible local practice. The most sensitive method for the detection of oligoclonal immunoglobulin bands is isoelectric focusing. The same amounts of IgG in parallel CSF and serum samples are used and oligoclonal bands are revealed with IgG specific antibody staining. All laboratories performing isoelectric focusing should check their technique at least annually using "blind" standards for the five different CSF and serum patterns. Quantitative measurements of IgG production in the CNS are less sensitive than isoelectric focusing. The preferred method for detection of blood-CSF barrier dysfunction is the albumin quotient. The CSF albumin or total protein concentrations are less satisfactory. These results must be interpreted with reference to the age of the patient and the local method of determination. Cells should be counted. The normal value is no more than 4 cells/microliters. Among evolving optional tests, measurement of the combined local synthesis of antibodies against measles, rubella, and/or varicella zoster could represent a significant advance if it offers higher specificity (not sensitivity) for identifying chronic rather than acute inflammation. Other tests that may have useful correlations with clinical indices include those for oligoclonal free light chains, IgM, IgA, or myelin basic protein concentrations.

Development and evaluation of antibody-MHC/peptide conjugates as a new form of cancer immunotherapy

Summary One of the major goals of cancer immunotherapy is the induction of a specific and effective antitumor cytotoxic T lymphocyte (CTL) response. However, the downregulation of Class I Major Histocompatibility Complexes (MHC) expression and the low level of tumor peptide presentation on tumor cell surface, ás well as the low immunogenicity of tumor specific antigens, limit the effectiveness of anti-tumor CTL responses. On the other hand, monoclonal antibodies, which bind with high affinity to tumor cell surface markers, are powerful tumor targeting tools. However, their capacity to .kill cancer cells is limited and mAb cancer treatments usually require the addition of different form of chemotherapy. The new cancer immunotherapy strategy described herein combines the advantage of the high tumor targeting capacity of monoclonal antibodies (mAb) with the powerful cytotoxicity of CD8 T lymphocytes directed against highly antigenic peptide-MHC complexes. Monoclonal antibody Fab fragments directed against a cell surface tumor associated antigen (TAA) are chemically coupled to soluble MHC class I complexes carrying a highly antigenic peptide. Antibody guided targeting and oligomerization of numerous antigenic class IMHC/peptide complexes on tumor cell surfaces can redirect the cytotoxicity of peptide-specific CD8 T cells towards target cancer cells. After the description of the production of murine anti-tumor xMHC/peptide conjugates in the first part of this thesis, the therapeutic potential of such conjugates were sequentially investigated in different syngeneic tumor mouse models. As a first proof of principle, transgenic OT-1 mice and later CEA transgenic C57BL/6 (B6) mice, adoptively transferred with OT-1 spleen cells and immunized with ovalbumin, were used as a model of high frequency of ova peptide specific T cells. In these mice, growth inhibition and regression of palpable colon carcinoma expressing CEA, were obtained by systemic injection of anti-CEA Fab/H-2Kb/ova peptide conjugates. Next, LCMV virus and influenza virus infection of B6 mice were used as viral models to redirect natural antiviral CTL responses to tumors via conjugates loaded with viral peptides. We showed that in mice infected with the LCMV virus, subcutaneous CEA-expressing tumor cells were inhibited by the H2Db/GP33 restricted anti-viral CTL response when preincubated before grafting with anti-CEA Fab-H-2Db/GP33 peptide conjugates. In mice infected with the influenza virus, lung metastases expressing the HER2 antigen were inhibited by the H-2Db/NP366 restricted CTLs response when preincubated before injection with anti-Her2 Fab-H-2Db/NP366 peptide conjugates. In the last chapter, the stability of the peptide in the anti-CEA Fab-H-2Db/GP33 conjugates was improved by the covalent photocross-link of the GP33 peptide in the H-2Db MHC groove. Thus, LCMV immune mice could reject CEA expressing tumors when treated with systemic injections of anti-CEA FabH-2Db/GP33 cross-linked conjugates. These results are encouraging for the potential application of this strategy in clinic. Such conjugates could be used alone in patients boosted by the relevant virus, or used in combination with existing T cell based ìmmunotherapy. Résumé Une des principales approches utilisées dans l'immunothérapie contre le cancer consiste en l'induction d'une réponse T cytotoxique (CTL) spécifiquement dirigée contre la tumeur. Cependant, le faible niveau d'expression des complexes majeurs d'histocompatibilité de classe I (CMH I) et de présentation des peptides tumoraux à la surface des cellules cancéreuses ainsi que la faible immunogenicité des antigens tumoraux, limitent l'efficacité de la réponse CTL. D'autre part,. l'injection d'anticorps monoclonaux (mAb), se liant avec une haute affinité aux marqueurs de surface des cellules tumorales, a fourni des résultats cliniques encourageant. Cependant l'efficacité de ces mAbs contre des tumeur solides reste limitée et necessite souvent l'addition de chimiotherapie. La nouvelle stratégie thérapeutique décrite dans ce travail associe le fort pouvoir de localisation des anticorps monoclonaux et le fort pouvoir cytotoxique des lymphocytes T CD8+. Des fragments Fab d'anticorps monoclonaux, dirigés contre des antigènes surexprimés à la surface de cellules tumorales, ont été chimiquement couplés à des CMH I solubles, portant un peptide fortement antigénique. Le ciblage et l'oligomérisation à la surface des cellules tumorales de nombreux CMH I présentant un peptide antigénique, va réorienter la cytotoxicité des cellules T CD8+ spécifiques du peptide présenté, vers les cellules tumorales cibles. Après une description de la production de conjugé anti-tumeur x CMH Upeptide dans la première partie de cette thèse, le potentiel thérapeutique de tels conjugés a été successivement étudiés in vivo dans différents modèles de tumeur syngénéiques. Tout d'abord, des souris OT-1 transgéniques, puis des souris C57BL/6 (B6) transférées avec des cellules de rate OT-1 puis immunisées avec l'ovalbumine, ont été employées comme modèle de haute fréquence de cellules T CD8+ spécifiques du peptide ova. Chez ces souris, l'inhibition de la croissance et la régression de nodules palpables de carcinomes exprimant l'antigène caccino embryonaire (ACE), ont été obtenues par l'injection systémique de conjugés anti-ACE Fab/H-2Kb/ova. Par la suite, l'infection de souris B6 par le virus LCMV et par le virus de la grippe, ont été utilisés comme modèles viraux pour redirigées des réponses anti-virales naturelles vers les tumeurs, en utilisant des conjugés chargés avec des peptides viraux. Nous avons montré que .chez les souris infectées par le LCMV, la croissance de carcinome sous-cutané est empêchée par la réponse anti-virale, spécifique du complexe H2Db/GP33, lorsque les cellules tumorales greffées sont pré-incubées avec des conjugés anti-CEA Fab-H-2Db/GP33. Dans le cas de souris infectées par le virus de la grippe, la métastatisation de mélanomes pulmonaires exprimant l'antigène HER-2 est inhibée par la réponse anti-virale spécifique du complexe H-2Db/NP366, après pré-incubation des cellules tumorales avec des conjugés anti-Her2 FabxH-2Db/NP366. Dans le dernier chapitre, la liaison covalente du peptide GP33 dans le complexe H-2Db a amélioré la stabilité des conjugés correspondants et a permis le traitement systémique de souris greffées avec des tumeurs exprimant l'ACE et infectées par le LCMV. L'ensemble de ces résultats sont encourageant pour l'application de cette strategie en clinique. De tels conjugués pourraient être employés seuls ou en combinaison avec des protocols d'immunisation peptidique anti-tumoral. Résumé pour un large public Dans les pays industrialisés, le cancer se situe au deuxième rang des causes de mortalité après les maladies cardiovasculaires. Les principaux traitement de nombreux cancers sont la chirurgie, en association avec la radiothérapie et la chimiothérapie. L'immunothérapie est l'une des nouvelles approches mises en oeuvre pour la lutte contre le cancer. Elle peut être humorale, et s'appuyer alors sur la perfusion d'anticorps monoclonaux dirigés contre des antigènes tumoraux, par exemple les anticorps dirigés contre les protéines oncogéniques Her-2/neu dans le cancer du sein. Ces anticorps ont le grand avantage de spécifiquement se localiser à la tumeur et d'induire la lyse ou d'inhiber la proliferation des cellules tumorales exprimant l'antigène. Certains sont utilisés en clinique pour le traitement de lymphomes, de carcinomes de l'ovaire et du sein ou encore de carcinomes metastatiques du côlon. Cependant l'efficacité de ces anticorps contre des tumeurs solides reste limitée et les traitements exigent souvent d'être combiner avec de la chimiothérapie. L'immunothérapie spécifique peut également être cellulaire et reposer sur une démarche de type vaccinal, consistant à générer des lymphocytes T cytotoxiques (cytotoxic T lymphocytes :CTL) capables de détruire spécifiquement les cellules malignes. Pour obtenir une réponse lymphocytaire T cytotoxique antitumorale, la cellule T doit reconnaître un antigène associé à la tumeur, présenté sous forme de peptide dans un complexe majeur d'histocompatibilité de classe I. Or les cellules tumorales ne presentent pas efficacement les peptides antigèniques, car elles se caractérisent par une diminution ou une absence d'expression des antigènes d'histocompatibilité de classe I, des molécules d'adhésion et des cytokines costimulatrices, et par une faible expression des antigènes associés aux tumeurs. C'est en partie pourquoi, malgré l'induction de fortes réponses CTL specifiquement dirigés contre des antigens tumoraux, les régressions tumorales obtenus grace à ces vaccinations sont relativement rares. Alors que chez les personnes atteintes du cancer on observe l'instauration d'une tolérance immunitaire vis-à-vis de la tumeur, à l'inverse, notre systeme immunitaire reste parfaitement capable de combattre des infection virales classiques, tels que la grippe, qui font aussi appel à une réponse T cytotoxique. Notre groupe de recherche a donc eu l'idee de développer une nouvelle approche thérapeutique où une réponse immunitaire anti-virale très efficace serait redirigée vers les tumeurs par des anticorps monoclonaux. Concrètement, nous avons chimiquement couplés des fragments d'anticorps monoclonaux dirigés contre des antigènes surexprimés à la surface de cellules tumorales, à des CMH I portant un peptide viral antigénique. Les cellules tumorales, ciblées par le fragment anticorps et couvertes d' antigènes viraux présentés par des molécules de CMH I, peuvent ainsi tromper les lymphocytes cytotoxiques anti-viraux qui vont détruire les cellules tumorales comme si elles étaient infectées par le virus. Suite à des résultats prometteurs obtenus in vitro avec différents conjugués anticorps-CMH humain de type HLA.A2/peptide Flu, le but du projet était de tester in vivo des conjugués anticorps-CMH I murins sur des modèles expérimentaux de souris. Tout d'abord, des souris transgéniques pour un recepteur T specifique du peptide ova, puis des transferts adoptifs de ces cellules T specifiques dans des souris immunocompétentes, ont été choisi comme modèle de haute fréquence des cellules T spécifiques, et ont permi de valider le principe de la strategie in vivo. Puis, deux modèles viraux ont été elaboré avec le virus LCMV et le virus Influenza, pour réorienter des réponses antivirales naturelles vers les tumeurs grâce à des conjugés chargés avec des peptides viraux. Nous avons montré la grande capacité de nos conjugués à rediriger des réponses cytotoxiques vers les tumeurs et inhiber la croissance de tumeurs syngénéiques sous cutanés et pulmonaires. Ces résultats d'inhibition tumorales obtenus dans des souris immunocompétentes, grâce à l'injection de conjugués anticorps xCMH/peptide et réorientant deux réponses antivirales différentes vers deux modèles tumoraux syngeneiques, sont encourageant pour l'application de cette nouvelle stratégie en clinique.

Comunicação interna como factor de motivação.Estudo de casoTACV

Este trabalho tem por finalidade analisar a relação existente entre a comunicação interna e a motivação dos colaboradores dos TACV Cabo Verde Airlines. A comunicação interna é uma ferramenta fundamental para a elevação da motivação de colaboradores de qualquer organização. O sistema organizacional se viabiliza graças ao sistema de comunicação nele existente, pois permitirá sua continua realimentação e sua sobrevivência. Assim esse sistema é fundamental para o processamento das funções administrativas internas. (KUNSCH, 2003). Esta pesquisa cujo tema é Comunicação Interna como Factor de Motivação, tem como objectivo principal, descobrir a influência da comunicação interna na motivação dos colaboradores dos TACV. Propôs-se ainda descobrir o grau de motivação dos colaboradores bem como analisar a importância da comunicação para a elevação da motivação dos mesmos. De forma a esclarecer a hipótese de que a comunicação interna pode ou não influenciar a motivação, será feito o estudo com base na teoria dos Dois Factores de Frederick Herzeberg. Foi nessa óptica que se despertou o interesse por esse tema no sentido de dar algum contributo para a organização em estudo. Para a aquisição de informações, foi aplicado questionários do tipo misto, fechado, aplicados aos 42 colaboradores com a idade compreendia entre os 21 e os 55, tendo em conta a amostra estratificada de 10% sobre o total dos colaboradores de cinco departamentos escolhidos. Os departamentos escolhidos para o estudo foram: Comercial, Financeiro, Handling, Manutenção e Operações. No questionário destacou-se primeiramente com a identificação e caracterização dos colaboradores mediante sexo, idade, profissão e nível de escolaridade, seguido de, questões relacionadas com a comunicação, relacionamentos, valorização, imagem da empresa e finalmente, questões motivacionais. As informações recolhidas foram primeiramente introduzidas no Excel e depois no programa SPSS como forma de serem melhores analisadas e obter resultados satisfatórios capazes de responder as inquietações surgidas anteriormente, se de facto a comunicação veiculada nos TACV, influencia a motivação dos colaboradores. Após as análises saiu a conclusão de que realmente a comunicação veiculada nos TACV é satisfatória e influencia a motivação dos colaboradores.

Micro-patterning of biomolecules on polymer substrates.

UV−excimer laser photoablation was used, in combination with surface blocking techniques, to pattern proteins on the surfaces of polyimide and poly(ethylene terephthalate). This technique involves physical adsorption of avidin through laser-defined openings in low-temperature laminates or adsorbed protein blocking layers. Visualization of biomolecular patterns were monitored using avidin and fluorescein-labeled biotin as a model receptor−ligand couple. Adsorbed proteins could be shown to bind to UV-laser-treated polymer surfaces up to three times higher than on commercially available polymers. UV-laser photoablation was also used for the generation of three-dimensional structure, which leads to the possibility of biomolecule patterning within polymer-based microanalytical systems. The simplicity and easy handling of the described technique facilitate its application in microdiagnostic devices.

Ex post bargaining, labor coordination and wage formation at the firm level

We lay out a model of wage bargaining with two leading features:bargaining is ex post to relevant investments and there isindividual bargaining in firms without a Union. We compareindividual ex post bargaining to coordinated ex post bargainingand we analyze the effects on wage formation. As opposed to exante bargaining models, the costs of destroying the employmentrelationship play a crucial role in determining wages. Highfiring costs in particular yield a rent for employees. Ourtheory points to a employer size-wage effect that is independentof the production function and market power. We derive a simpleleast squares specification from the theoretical model thatallow us to estimate components of the wage premium fromcoordination. We reject the hypothesis that labor coordinationdoes not alter the extensive form of the bargaining game. Laborcoordination substantially increases bargaining power butdecreases labor's ability to pose costly threats to the firm.

Optimal contracts, adverse selection and social preferences: An experiment

It has long been standard in agency theory to search for incentive-compatible mechanisms on the assumption that people care only about their own material wealth. However, this assumption is clearly refuted by numerous experiments, and we feel that it may be useful to consider nonpecuniary utility in mechanism design and contract theory. Accordingly, we devise an experiment to explore optimal contracts in an adverse-selection context. A principal proposes one of three contract menus, each of which offers a choice of two incentive-compatible contracts, to two agents whose types are unknown to the principal. The agents know the set of possible menus, and choose to either accept one of the two contracts offered in the proposed menu or to reject the menu altogether; a rejection by either agent leads to lower (and equal) reservation payoffs for all parties. While all three possible menus favor the principal, they do so to varying degrees. We observe numerous rejections of the more lopsided menus, and approach an equilibrium where one of the more equitable contract menus (which one depends on the reservation payoffs) is proposed and agents accept a contract, selecting actions according to their types. Behavior is largely consistent with all recent models of social preferences, strongly suggesting there is value in considering nonpecuniary utility in agency theory.

As Línguas de Cabo Verde: uma Radiografia Sociolinguística

Esta dissertação constitui um estudo de caso, exploratório e de carácter descritivo. Tem como objectivo fazer uma radiografia sociolinguística de Cabo Verde, particularmente centrada no actual uso das duas línguas faladas no arquipélago, o português (PCV) e o crioulo cabo-verdiano (LCV). A linha de pesquisa adoptada inspira-se fortemente nos estudos de macrosociolinguística, tomando a situação de contacto de línguas, caracterizadora da sociedade cabo-verdiana, como ponto de partida para o enquadramento de um conjunto de questões seleccionadas para investigação mais aprofundada. São, assim, explorados os processos implicados nesta situação de contacto concreta e os resultados linguísticos decorrentes da mesma, como o bilinguismo ou a diglossia (cf. Cap. 3). Recorrendo a contributos teóricos de áreas associadas e complementares (cf. Cap. 1), foca-se a importância da análise dos domínios em que cada uma das línguas é usada, das redes sociais dos falantes ou das suas atitudes linguísticas. A investigação partiu de uma recolha de dados realizada para o efeito, nas nove ilhas habitadas. As unidades de análise retidas correspondem a uma amostragem de dois grupos sociais distintos: falantes jovens, alunos do ensino secundário (inquiridos por questionário), e falantes adultos cuja profissão implica uma intensa actividade linguística (professores e ‘líderes’, inquiridos por entrevistas semi-dirigidas). Foi usada uma metodologia de recolha o mais rigorosa possível e adoptado o tratamento estatístico de dados (cf. Cap. 2). O confronto dos comportamentos linguísticos e das atitudes das duas gerações inquiridas, com diferentes características (cf. Introdução), forneceu importantes informações sobre a dinâmica linguística da sociedade cabo-verdiana, conclusões essas que serão importantes para a definição de orientações no âmbito da política linguística (cf. Cap. 5). É apresentada, como complemento, uma análise exploratória de alguns aspectos sintácticos atestados nas produções dos indivíduos inquiridos com instrução superior (cf. Cap. 4), um contributo, embora modesto, para a definição da variedade padrão do PCV

On ignoring scientific evidence: The bumpy road to enlightenment

It is well accepted that people resist evidence that contradicts their beliefs.Moreover, despite their training, many scientists reject results that are inconsistent withtheir theories. This phenomenon is discussed in relation to the field of judgment anddecision making by describing four case studies. These concern findings that clinical judgment is less predictive than actuarial models; simple methods have proven superiorto more theoretically correct methods in times series forecasting; equal weighting ofvariables is often more accurate than using differential weights; and decisions cansometimes be improved by discarding relevant information. All findings relate to theapparently difficult-to-accept idea that simple models can predict complex phenomenabetter than complex ones. It is true that there is a scientific market place for ideas.However, like its economic counterpart, it is subject to inefficiencies (e.g., thinness,asymmetric information, and speculative bubbles). Unfortunately, the market is only correct in the long-run. The road to enlightenment is bumpy.

Pollinator guild organization and its consequences for reproduction in three synchronopatric species of Tibouchina (Melastomataceae)

Pollinator guild organization and its consequences for reproduction in three synchronopatric species of Tibouchina (Melastomataceae). In co-flowering plant species, pollinator sharing can result in interspecific pollen transfer and fecundity reduction. Competition will be relaxed whenever there is a large amount of initial pollen supply or if each plant species occupies different habitat patches. Reproduction in Tibouchina cerastifolia (Naudin) Cogn., T. clinopodifolia (DC.) Cogn. and T. gracilis (Bonpl.) Cogn. was studied in an area of Atlantic rainforest to examine whether synchronopatry induces time partitioning among pollinator species. Eleven bee species comprised the pollinator guild. Among pollinators, there were overlaps in bee species composition and in flower visitation time. Direct competition for pollen in Tibouchina Aubl. at the study site seems to lead to different activity periods among the bee species, in which Bombus pauloensis Friese,1913 was most active earlier, while the other species were active later in the day. Bombus pauloensis, the largest bee species recorded on Tibouchina flowers, was the most important and efficient pollinator. This species harvested pollen before the other species and had the shortest handling time. The plants reproduced sexually by selfing or outcrossing, and hybridization was not avoided by incompatibility reactions at the style. The avoidance of direct competition for pollen and no pollinator partitioning among the synchronopatric species of Tibouchina may reflect a facilitative interaction among these pioneer plants.