ABSTRACT Global warming potential (GWP) of rice paddies depends on straw management. This study evaluated methane (CH4) and nitrous oxide (N2O) emissions and soil C stocks to determine GWP and yield-scaled GWP under different strategies and intensities of rice straw management in a subtropical climate. We hypothesized that decreasing soil management intensity and straw incorporation in the soil would reduce GWP. Methane fluxes were substantially higher during the rice growing season than in the off-season, while the opposite was observed for N2O fluxes. The cumulative emissions of CH4 during the growing season among the straw management strategies evaluated ranged from 165.8 to 586.0 kg ha-1. Annual CH4 emissions were lower when soil and straw received some type of management compared to no-tillage. Daily N2O fluxes ranged from -2.8 to 201.7 g ha-1 day-1; cumulative N2O emissions during the off-season ranged from 455.2 to 2816.5 g ha-1. During the off-season, strategies to reduce N2O emissions include post-harvest straw incorporation using a disc harrow, winter straw removal, and ryegrass cropping. Soil organic C stocks ranged from 35.96 to 38.36 Mg ha-1. Straw management using a disc harrow reduced soil organic C stocks, with more adverse effects than straw removal. Soil and rice straw management did not affect rice grain yield, with an average of 10.4 Mg ha-1. Methane emissions were the main component of GWP in all straw management systems. The contribution of N2O emissions to GWP was small and mostly (>85 %) determined by off-season emissions. Yield-scaled GWP ranged from 0.64 to 1.06 Mg CO2eq Mg-1 yield and was lower when soil and straw management systems occurred shortly after the rice harvest. Our results indicate that soil and straw management immediately after rice harvest reduces CH4 emissions, GWP, and yield-scaled GWP.

Objective: To conduct Brazil’s first clinical trial employing 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy for post-traumatic stress disorder (PTSD), given its high prevalence resulting from epidemic violence. Methods: Of 60 volunteers, four matched the inclusion & exclusion criteria. Three patients with PTSD secondary to sexual abuse (diagnosed by the Structured Clinical Interview for DSM-IV and the Clinician Administered PTSD Scale for DSMV-4 [CAPS 4]) completed enrollment and treatment, following a standardized Multidisciplinary Association for Psychedelic Studies protocol consisting of 15 weekly therapy sessions: three with orally administered MDMA with concurrent psychotherapy and music, spaced approximately 1 month apart. CAPS-4 scores two months after the final MDMA session were the primary outcome. Results: No serious adverse events occurred. The most frequent adverse events were somatic pains and anguish. CAPS-4 reductions were always greater than 25 points. The final scores were 61, 27, and 8, down from baseline scores of 90, 78, and 72, respectively. All reductions were greater than 30%, which is indicative of clinically significant improvement. Secondary outcomes included lower Beck Depressive Inventory scores and higher Post-Traumatic Growth Inventory and Global Assessment of Functioning scores. Conclusions: Considering the current limitations in safe and efficacious treatments for PTSD and recent studies abroad with larger patient samples, MDMA-assisted psychotherapy could become a viable treatment in Brazil. Clinical trial registration: RBR-6sq4c9

Resumo A anatomia foliar ecológica do gênero Myrcia DC. ainda é pouco estudada. A espécie Myrcia guianensis (Aubl.) DC., popularmente conhecida como mapirunga, ocorre em região de litoral no estado do Ceará e possui importância ecológica e potencial medicinal. Objetivou-se caracterizar a anatomia foliar ecológica dessa espécie nas estações de chuva e seca, bem como, ao sol e à sombra na Restinga cearense. Para isso, foram realizadas coletas no Jardim Botânico de São Gonçalo de folhas totalmente expandidas e fixadas em FAA70, sendo substituído por etanol 70% após 24 horas. Seguiu-se para os procedimentos anatômicos usuais no Laboratório de Ecologia da Universidade Estadual do Ceará, a fim de analisar qualitativamente e quantitativamente as estruturas da lâmina foliar, pecíolo e paradérmico. Como resultados obteve-se a presença de características que contribuem para sua sobrevivência em ambiente de Restinga com períodos de deficit hídrico e alta taxa de luminosidade, tais como: presença de cutícula levemente espessa, folha hipoestomática, aumento da densidade estomática em folhas de sol, presença de fibras abundantes nos feixes vasculares da nervura central e presença de drusas. Portanto, conclui-se que a planta em estudo possui grande capacidade aclimatativa às condições analisadas (intensa luminosidade e períodos de deficit hídrico).

Abstract The ecological foliar anatomy of the genus Myrcia DC. is still little studied. Myrcia guianensis (Aubl.) DC. species popularly known as mapirunga, occurs in a coastal region in the state of Ceará and has ecological importance and medicinal potential. The objective was to characterize the ecological foliar anatomy of this species in rainy and dry seasons, as well as, in the sun and shade in the Ceará’s Restinga. To do so, samples were collected in São Gonçalo Botanical Garden, with leaves totally expanded and fixed in FAA70, being replaced by 70% ethanol after 24 hours. It was followed to the usual anatomical procedures in the Ecology Laboratory of the Ceará State University, in order to qualitatively and quantitatively analyze the structures of the leaf blade, petiole and paradermal sections. The results showed the presence of characteristics that contribute to its survival in a Restinga environment with periods of water deficit and high luminosity, such as: presence of slightly thick cuticle, hypoestomatic leaf, increased stomatal density in leaves of sun, presence of abundant fibers in the vascular bundles of the central vein and presence of drusen. Therefore, it is concluded that the plant under study has a great acclimative capacity to the analyzed conditions (intense luminosity and periods of water deficit).

RESUMO (O papel da Feira de Ciências como estratégia motivadora para o ensino de Botânica na educação básica). O ensino de Botânica é marcado por inúmeros problemas, como escassez de metodologias que motivem os alunos. Assim, foi proposto aos alunos das disciplinas de Botânica da Licenciatura em Ciências Biológicas da Universidade Estadual do Ceará a elaboração de uma Feira de Ciências, com conteúdo exclusivamente botânico utilizando mapa conceitual e outro material de livre escolha. A feira ocorreu em uma escola da rede pública de Fortaleza, CE, Brasil, com participação de alunos de 9° ano ao 3º ano do Ensino Médio. Após sua realização, foi aplicado um questionário aos graduandos de forma a compreender a percepção deles a respeito da atividade. Observou-se que necessitam de uma série de fatores que possibilitem sua execução, dentre eles disponibilidade de recursos e tempo hábil para executá-la. Portanto, conclui-se que essa metodologia desperta o interesse dos alunos pelos assuntos abordados, desde que haja suporte para tal, podendo servir de complemento à metodologia exclusivamente expositiva.

ABSTRACT (The role of the Science Fair as a motivating strategy for teaching Botany in basic education). Botany teaching is marked by numerous problems, among them is the lack of methodologies to generate motivation in students. Thus, it was offered to the students of the subjects of Botany in Biological Sciences degree at the Universidade Estadual do Ceará to prepare teaching materials to compose a science fair, with only botanical content. The objective was to evaluate this alternative strategy and conceptual map as motivating factors for teaching botany. The fair took place in a school of the public network of Fortaleza, Ceará State, Brazil, with participation of students from 9th grade to 3rd year of high school. After the fair, a questionnaire was applied to students. It was realized that teaching strategies as the science fair require a number of factors that enable it to occur successfully, including the availability of resources and the time for performing it. Therefore, it was verified that this teaching strategy is a valuable tool that arouses students’ interest for the subjects and it may serve to complement traditional exhibition methodology.

Este estudo teve por objetivo avaliar o potencial energético da matéria-prima residual produzida na colheita ou processamento de culturas agrícolas e florestais, in natura e carbonizada. O experimento resultou em um delineamento inteiramente casualizado, sendo cinco tratamentos: casca de café (Coffea arabica L.); palha de feijão (Phaseolus vulgaris L. cv. Carioca); descartes de madeira de construção civil e de madeireira, na forma de serragem; e sabugo de milho (Zea mays L.) e três repetições. As propriedades avaliadas foram: granulometria, densidade do granel, análise elementar, análise imediata, poder calorífico e densidade energética. Ao final do estudo pôde-se concluir que a casca de café apresenta melhores propriedades para uso em combustão direta dentre os resíduos in natura estudados, enquanto que o carvão de resíduos de madeira apresentou as melhores propriedades energéticas dentre os resíduos carbonizados.

This work aimed to characterize and evaluate the potential energy production of both raw and carbonized residues from harvest and product processing of agriculture and forest crops. The experiment resulted in a completely randomized design with five treatments and three replicates. The evaluated properties were: granulometry, bulk density, elemental analysis, immediate analysis, calorific value and energy density. The data were submitted to analysis of variance and means were compared using the Tukey test at 5% significance. In conclusion, the in natura coffee bark presented the best properties for use in direct combustion, while wood residues charcoal presented better properties for energetic purposes among carbonized residues in study.

Resumo A presente pesquisa objetivou realizar um inventário fitossociológico qualiquantitativo, do tipo censo, das ruas e avenidas da zona urbana dos municípios de Beberibe e Cascavel, Ceará. A análise foi realizada no período de ago/2014 à jul/2016. Foram inventariados 636 indivíduos, sendo 512 de Cascavel e 124 de Beberibe, distribuídos em 18 espécies e 12 famílias, das quais Azadirachta indica A. Juss. (Meliaceae) foi a mais representativa. Outras espécies em destaque foram: Syzygium malaccense (L.) Merr. & L.M. Perry (8,33%), Ficus benjamina L. (5,35%) e Gossypium arboreum L. (2,99%). Há um elevado percentual (98,74%) de plantas exóticas, inclusive dentre as espécies frutíferas. Em geral Beberibe apresenta plantas de menor porte e melhor estado geral; Cascavel apresenta plantas com mais danos e menor fitossanidade, tal fato pode ser explicado pelo menor índice de diversidade (H’=0,4) e maior quantidade de podas. Logo, pondera-se que o estudo da arborização urbana é necessário e importante para assessorar a gestão pública.

Abstract The objective of this study was to carry out a quali-quantitative phytosociological inventory and assessment along the streets and avenues of the urban zone of the municipalities of Beberibe and Cascavel (Ceará state). The trees were analyzed from August 2014 to July 2016. A total of 636 individuals were inventoried, 512 in Cascavel and 124 in Beberibe, distributed in 18 species and 12 families, of which Azadirachta indica A. Juss. (Meliaceae) was the most representative one. The other featured species were: Syzygium malaccense (L.) Merr. & L.M. Perry (8,33%), Ficus benjamina L. (5,35%) e Gossypium arboreum L. (2,99%). There was a high percentage (98.74%) of exotic species, including among the fruit species. In general, the trees in Beberibe were found to be smaller, with better general health. Cascavel presents plants with more damage and less phytosanitary, this fact can be explained by the lower diversity index (H ‘= 0.4) and higher amount of pruning. The study of urban arborization is important to support public management.

ABSTRACT Cover crops have numerous benefits when used in a no-till system. Understanding the processes of decomposition and N release of summer cover crops (SCC) may help select species and management to be used in cropping systems. This study aimed to evaluate C and N loss of SCC shoots. Six SCCs were evaluated: velvet bean (Mucuna aterrima), pearl millet (Pennisetum americanum), dwarf pigeon pea (Cajanus cajan), sunn hemp (Crotalaria juncea), showy rattlebox (Crotalaria spectabilis), and jack bean (Canavalia ensiformis). The experiment was conducted for two years under no-till in soil classified as Typic Hapludalf (Argissolo). The C and N remaining of crop shoots were evaluated for 140 days using litter bags and the results were fitted with a simple nonlinear regression model. Elevated air temperature and rainfall volume accelerated C and N loss in the first year. Carbon and N loss was characterized by a rapid initial phase followed by a slower one. Jack bean had the highest C loss rates, while the lowest rates were found in pearl millet. Velvet bean and pearl millet had the lowest N loss rates in the first year, together with showy rattlebox in the second year. The rates of C (kC) and N (kN) loss were positively correlated with total N and water-soluble C and N in crop shoots. During the 35 days after cover crop termination, SCCs released 35 to 137 kg ha-1 N in 2010 and 5 to 66 kg ha-1 N in 2011. Velvet bean and showy rattlebox showed more gradual N release, which may favor the synchronization between N release and N uptake by the succeeding crop. The sunn hemp was the legume species that combined higher remaining residues on the soil surface, releasing less N but preventing soil erosion.

Resumo A espécie Eugenia punicifolia (Kunth) DC. (murta) ocorre em região de litoral, no Estado do Ceará, e possui importância ecológica e medicinal. A presente pesquisa objetivou caracterizar a anatomia foliar da murta (E. punicifolia), nas estações de chuva e seca, bem como ao sol e à sombra, na Restinga cearense, pretendendo contribuir para a compreensão das variações morfoanatômicas em resposta às condições naturais de ocorrência da espécie. Para isso, foram realizadas coletas, no Parque Estadual Botânico do Ceará, de folhas totalmente expandidas e fixadas em FAA70, sendo substituído por etanol a 70%, após 24 horas. Seguiu-se para os procedimentos anatômicos usuais, a fim de analisar qualitativa e quantitativamente as estruturas da lâmina foliar, do pecíolo e da epiderme. Como resultado obteve-se que a murta apresenta características xeromórficas, como cutícula espessa, folha hipoestomática e fibras de esclerênquima nos feixes vasculares da nervura mediana. Portanto, conclui-se que a E. punicifolia possui grande plasticidade por conseguir ajustar-se bem nas condições analisadas.

Abstract The species Eugenia punicifolia (Kunth) DC. (myrtle) occurs in the coastal region of the state of Ceará and has ecological and medicinal importance. This study aimed to characterize the leaf anatomy of myrtle (E. punicifolia) in the rainy and dry seasons, as well as in the sun and shade in the restinga region of the state of Ceará and to contribute to the understanding of the morphoanatomic variations in response to the natural conditions of the occurrence of this species. For this, collections of fully expanded leaves were performed at the Botanical Park of Ceará and fixed in FAA70, being replaced by 70% ethanol after 24 hours. The usual anatomical procedures were then performed in order to qualitatively and quantitatively analyze the leaf blade, petiole and epidermis structures. As a result, it was found that myrtle has xeromorphic characteristics such as thick cuticle, hypoestomatic leaf and sclerenchyma fibers in the median vein vascular bundles. It was concluded that E. punicifolia has great plasticity to adjust well under the analyzed conditions.

RESUMO: O Rio Grande do Sul possui cerca de 20% da área total de solos de terras baixas, propícias para o cultivo do arroz (Oryza sativa) irrigado por inundação. Buscando mitigar danos ocasionados com o monocultivo de arroz, novas culturas, como o sorgo (Sorghum bicolor) e a soja (Glycine max), têm sido cultivadas nestas áreas. Com diferentes qualidades de resíduos culturais, espera-se uma alteração na dinâmica da matéria orgânica do solo (MOS) e, consequentemente, do nitrogênio (N). O objetivo deste estudo foi avaliar a influência de resíduos culturais de arroz, soja e sorgo na quantidade de N em frações físicas da MOS de dois solos de terras baixas, utilizando a técnica de marcação isotópica de 15N das culturas e uma incubação por um ciclo de 180 dias em condição aeróbica e mais 180 dias em condição anaeróbica. Aos 30, 180 e 360 dias de incubação foi quantificado o N remanescente dos resíduos vegetais e destino do N proveniente dos resíduos nos dois solos em frações físicas da MOS >250 μm, 250-53 μm e <53 μm. O solo com maior quantidade de argila+silte recebeu maior quantidade de 15N dos resíduos, enquanto que o alagamento do solo após 180 dias de incubação ocasionou uma perda do N adicionado ao solo pelos resíduos de soja e sorgo. De maneira geral, foram encontradas maiores quantidades de 15N na fração <53 μm, associado aos argilominerais. As perdas de N devem ser consideradas na adubação nitrogenada para as culturas sequentes nos sistemas de rotação de culturas com arroz irrigado.

ABSTRACT: The state of Rio Grande do Sul has about 20% of the total area as lowland soils, suitable for flooded rice (Oryza sativa). In order to mitigate damage caused by rice monoculture, new crops such as sorghum (Sorghum bicolor) and soybean (Glycine max) have been cultivated in these areas. With different qualities of crop residues, it is expected a change in soil organic matter (SOM) dynamics and consequently, nitrogen (N) availability. The objective of this study was to evaluate the influence of rice, soybean and sorghum crop residues on the N present in physical fractions of SOM of two lowland soils, using labeled 15N technique, under incubation for 180 days in aerobic condition and more 180 days in anaerobic condition. At 30, 180 and 360 days of incubation the remaining N of the plant residues and N destination from the residues in both soils were quantified in the physical fractions of SOM >250 μm, 250-53 μm and <53 μm. The soil with higher amount of clay+silt received a larger quantity of 15N from residues, while flooding of the soil after 180 days caused a loss of N added to the soil by the soybean and sorghum residues. In general, larger amounts of 15N were reported in the fraction <53 μm, associated with clay minerals, throughout the incubation period. These N losses should be considered in N fertilization for the following crops in rotation with flooded rice.

ABSTRACT Isotopic labeling of plants is useful in tracking the fate of carbon (C) from different plant parts in a soil-plant system when these parts decompose simultaneously. Pulse labeling is a relatively simple technique and is amenable for use in the field. Therefore, we evaluated a 13CO2 pulse-labeling method to label crop plants under subtropical field conditions for simultaneous root and shoot decomposition studies. Wheat (Triticum aestivum L.), pea (Pisum sativum L.), and vetch (Vicia sativa L.) plants were grown inside polyvinyl chloride (PVC) cylinders and pulse labeled once a week for a total of 11 times. After harvest, “paired” treatments were designed by combining 13C-labeled shoots with unlabeled roots and unlabeled shoots with 13C-labeled roots, resulting in six treatments (2 combinations × 3 species), plus an unamended control treatment. The 13C enrichment of plant parts, chemical fractions, 13C recovery, and distribution in roots, shoots, and soil were determined. Soil CO2 emissions were measured continuously by the alkaline trap method for 180 days. Plant dry matter production and chemical composition were not modified by 13C labeling. The maximum level of 13C enrichment (δ13C) in plants was +495 %o in wheat, +426 %o in pea, and +378 ‰ in vetch plants. All three crops showed similar patterns of 13C distribution in the following order: shoots > roots > soil. On average, 81 to 89 % of the recovered 13C was in the shoots, 7 to 14 % was in the roots, and 2.7 to 4.3 % was in the soil. The rate of C mineralization and cumulative C mineralization were not different between “paired” treatments of the three crops, showing that the paired treatments were equally degradable. The pulse-labeling technique used under field conditions allowed for production of sufficiently labeled wheat, pea, and vetch plants. Therefore, it is a practical approach with respect to resource demand (tracer and labor costs), and it is suitable for in situ labeling.

Resumo A espécie Eugenia luschnathiana (O.Berg) Klotzsch ex B.D.Jacks. (Myrtaceae), vulgarmente conhecida como pitomba-da-baía, ocorre em região de Restinga no Estado do Ceará e possui potencial medicinal. O presente estudo objetivou caracterizar a anatomia foliar da E. luschnathiana nas estações de chuva e seca, bem como ao sol e à sombra na Restinga cearense, visando a gerar informações úteis para a compreensão do valor aclimatativo das respostas morfoanatômicas às condições naturais de ocorrência da espécie. Foram realizadas coletas, no Parque Estadual Botânico do Ceará, de folhas completamente expandidas e fixadas em FAA70, sendo substituído por etanol a 70%, após 24 h. As amostras foram submetidas a metodologias-padrão em anatomia vegetal, a fim de analisar qualitativa e quantitativamente as estruturas da lâmina foliar e do pecíolo. Como resultado, verificaram-se diferenças entre folhas de sol e sombra na chuva e na seca. Em relação à luminosidade, a maioria das determinações foi maior nas folhas de sol: densidade e frequência de tricomas; frequência de cicatriz de tricomas; frequência estomática, índice estomático, comprimento, largura e área dos estômatos; espessura da lâmina foliar, mesófilo, cutícula, epiderme, parênquima paliçádico e esponjoso; comprimento e largura da nervura central, área do feixe vascular da nervura central, quantidade de cavidades secretoras na nervura central; comprimento e largura do pecíolo, área do feixe vascular do pecíolo, quantidade e área de cavidades secretoras no pecíolo. Nas folhas de sombra, apenas a quantidade de drusas na nervura central e no pecíolo foram maiores. Em relação à sazonalidade, todas as determinações foi maior na estação de chuva, com exceção do comprimento e da largura da nervura central; quantidade de drusas na nervura central e no pecíolo, comprimento do pecíolo, área do feixe vascular e das cavidades secretoras do pecíolo. Portanto, conclui-se que a E. luschnathiana possui grande capacidade aclimatativa às condições de intensa luminosidade e períodos de déficit hídrico.

Abstract Eugenia luschnathiana (O.Berg) Klotzsch ex B.D.Jacks. (Myrtaceae) species, commonly known as pitomba-da-baía, occurs in Restinga region in the state of Ceara and has medicinal potential. The present study aimed to characterize the anatomy of E. luschnathiana leaves in the rainy and dry seasons, as well as in the sun and shade in the Restinga region of Ceara, aiming to generate useful information to understand the adaptive value of morphoanatomic responses to the natural conditions of occurrence of the species. Collections were performed at the State Botanical Park of Ceara, and leaves were completely expanded and fixed in FAA70, being replaced by 70% ethanol after 24 h. Samples were submitted to standard plant anatomy methodologies in order to qualitatively and quantitatively analyze the leaf blade and petiole structures. As a result, there were differences among sun and shade leaves, rain and dry. In relation to luminosity, most determinations were higher in sun leaves: trichome density and frequency; trichome scar frequency; stomatal frequency, stomatal index, length, width and area of stomata; thickness of leaf blade, mesophyll, cuticle, epidermis, palisade and spongy parenchyma; length and width of the central vein, area of the central vein vascular bundle, number of secretory cavities in the central vein; length and width of the petiole, area of the petiole vascular bundle; amount and area of secretory cavities in the petiole. In shade leaves, only the number of druses in the central vein and petiole were larger. Regarding seasonality, all determinations were higher in the rainy season, except for the length and width of the central vein; number of druses in the central vein and petiole; length of the petiole, area of the vascular bundle and secretory cavities of the petiole. Therefore, it could be concluded that E. luschnathiana has great acclimative capacity to conditions of intense luminosity and periods of water deficit.

ABSTRACT Recycling of carbon (C) and nitrogen (N) from plants into soils is decisive for maintaining soil organic matter and soil fertility. Therefore, we quantified plant biomass and C and N in the shoots and roots from the topsoil layer for a wide range of annual crops grown under subtropical conditions. We grew 26 species, 13 main crops, and 13 cover crops, in the field in standard sowing arrangements. Root biomass was recovered from the 0.00-0.20 m soil layer at flowering, and shoot biomass was measured at flowering for all crops and at maturity only for the main crops. Root dry matter (DM) exhibited an average of 14.9 ± 5.7 % of the total shoot biomass at flowering, and the mean shoot DM to root DM ratio was 6.9 (2.8-15.0) for the 26 crops considered. Leguminous species had less root DM (0.5 to 1.0 Mg ha-1) than grass species (1.1 to 2.3 Mg ha-1). The shoot C to root C ratio varied consistently with DM, while the root N to shoot N ratio varied considerably among species. Proportionally more biomass, C, and N was allocated to the root systems of grasses (Poaceae species) than non-grass species (especially Fabaceae species). The findings of this study contribute to designing rotations to include species that promote cycling of N and have high potential for adding C to the soil through roots. In this sense, the use of intercropped grasses and legumes is a promising strategy, especially for cover crops.

Neste artigo adotamos uma metodologia de questionamento indireto para medir as opiniões de estudantes da UnB acerca do uso da cor/raça como um critério de admissão à Universidade. Partimos da hipótese de que opiniões sobre políticas afirmativas não são obtidas com confiabilidade em surveysconvencionais, pois o grupo não elegível ao benefício (no caso, os estudantes brancos) poderia ocultar uma resposta de oposição por receio de parecer preconceituoso. Esse efeito é conhecido na literatura como efeito da desejabilidade social. Portanto, adotamos uma metodologia que garante privacidade aos respondentes, denominada experimento de listas, para medir as opiniões sinceras dos estudantes acerca do sistema de cotas raciais. Porém os resultados mostraram que o viés nas opiniões ocorreu, de forma inesperada, no grupo de estudantes elegíveis às cotas (afrodescendentes e indígenas). Precisamente, eles apoiaram fortemente o sistema de cotas raciais (68,3%) quando tiveram privacidade nas respostas, mas na pergunta direta demonstraram apenas uma tímida aprovação (29,0%). Chamamos esse efeito de efeito de inibição. Paralelamente, os estudantes brancos não demonstraram nenhum efeito de desejabilidade social, contrariando alguns achados de pesquisas similares nos EUA.

In this article, we adopt an indirect questioning methodology to measure attitudes toward the use of race as a criterion for admission in Brazilian higher education institutions. We hypothesize that attitudes toward such affirmative action policies cannot be measured by conventional survey questions because non-eligible students - mostly white students - may fear to appear prejudiced by showing opposition to them. This survey effect is known as the social desirability effect. Thus we adopt a list experiment to measure students' sincere attitudes toward the race-based quota admission system. We find that white students do not over-report their approval of racial quotas in university admissions. But, the results show that quota eligible students, Afro and indigenous Brazilians, tend to overwhelmingly under-report their approval of race quotas. Specifically, eligible students strongly approve of the racial quota system (68.3%) when provided privacy in their responses, but publicly voice only timid approval of it (29.0%). We label this effect as the inhibition effect. Moreover, we did not find a social desirability effect among white students, contrasting with some previous findings in the U.S.