Effects of Self-Controlled Knowledge of Results on Learning a Taekwondo Serial Skill.

Allowing learners to control feedback has been an effective strategy in motor skills learning. However, most studies of self-controlled (SC) feedback have used simple tasks that may be dissimilar to sports skills that generally demand more degrees of freedom and cognition. Thus, this study investigated the effects of SC knowledge of results (KR) on learning a complex Taekwondo skill. Twenty-four undergraduate volunteers of both sexes, aged 18-35 years, practiced a specific serial Taekwondo skill that was novel to them. We divided participants randomly into SC and yoked groups and compared their performance after they learned a specific displacement sequence, finishing with a lateral kick (bandal-tchagui) at a punching bag within a target time span. During acquisition, all participants performed 48 trials divided into six blocks and, on a retention test 24 hours later, they performed 10 more trials. We found that both groups reduced their errors from the first to the last block of the acquisition phase and that the SC group showed a better performance on the retention test, relative to the yoked control group. SC KR participants requested KR mainly after good trials, though they showed no statistically significant differences between trials with and without KR. Their inefficiency in estimating their own errors may have been due to task complexity, since many aspects of the task beyond its temporal requirement demanded the learners' attention. Our results, using a novel Taekwondo serial skill, confirm and extend the benefits of SC KR from just simple motor learning in past studies to learning complex motor skills.

External Control of Knowledge of Results: Learner Involvement Enhances Motor Skill Transfer.

Providing the learner control over aspects of practice has improved the process of motor skill acquisition, and self-controlled knowledge of results (KR) schedules have shown specific advantages over externally controlled ones. A possible explanation is that self-controlled KR schedules lead learners to more active task involvement, permitting deeper information processing. This study tested this explanatory hypothesis. Thirty undergraduate volunteers of both sexes, aged 18 to 35, all novices in the task, practiced transporting a tennis ball in a specified sequence within a time goal. We compared a high-involvement group (involvement yoked, IY), notified in advance about upcoming KR trials, to self-controlled KR (SC) and yoked KR (YK) groups. The experiment consisted of three phases: acquisition, retention, and transfer. We found both IY and SC groups to be superior to YK for transfer of learning. Postexperiment participant questionnaires confirmed a preference for receiving KR after learner-perceived good trials, even though performance on those trials did not differ from performance on trials without KR. Equivalent IY and SC performances provide support for the benefits of task involvement and deeper information processing when KR is self-controlled in motor skill acquisition.

Atividade antimicrobiana do óleo essencial de Lippia origanoides e Lippia rotundifolia frente a enterobactérias isoladas de aves / Antimicrobial activity of Lippia origanoides and Lippia rotundifolia oils against enterobacteria isolated from poultry

The aim of this study was to evaluate the antimicrobial activity of essential oils on enterobacteria Escherichia coli and Staphylococcus aureus isolated from poultry fecal samples in the cloaca from 49 laying hens. To analyze the antimicrobial sensibility an agar diffusion susceptibility test was performed and the Minimum Inhibitory Concentration (MIC) and the Minimum Bactericida Concentration (MBC) of Lippia origanoides and Lippia rotundifolia essential oils was determined. The concentrations used were 160, 80 and 40 L/mL. The L. origanoides essential oil showed antimicrobial effect from 40 L/mL dose against both microorganisms, with larger efficiency in E. coli. The L.rotundifolia essential oil was more efficient at the concentration of 160L/mL. Its effect was observed in all microorganisms. These results suggest that L. origanoides oil is more effective than L. rotundifolia oil in inhibiting the growth of microorganism isolated from poultry, although it also has a satisfactory antimicrobial effect. Results indicate the potential use of these plant's essential oils in poultry feed as an alternative to conventional antimicrobial products.

Avaliação da atividade antibacteriana do óleo essencial de Lippia origanoides frente à Staphylococcus sp. isolados de alimentos de origem animal / Assessment of the antibacterial activity of the essential oil of Lippia origanoides in relation to Staphylococcus sp. isolated from food of animal origin

Objetivou-se no trabalho avaliar a ação antibacteriana do óleo essencial de Lippia origanoides frente à isolados de Staphylococcus sp. de alimentos de origem animal. Para tanto, realizou-se análise química da composição do óleo, teste de sensibilidade das bactérias frente a dez antibióticos de uso terapêutico e ao óleo essencial de Lippia origanoides, além da determinação da concentração inibitória mínima (CIM) e da concentração bactericida mínima (CBM). A análise cromatográfica do óleo apresentou o timol como composto majoritário (48,70%), além de pequena quantidade de carvacrol (1,14%). No teste de sensibilidade frente aos antibióticos, 75% dos isolados apresentaram resistência a, no mínimo, três antibióticos. Em relação ao óleo essencial, os isolados de Staphylococcus sp oriundos de leite bovino mostraram-se mais resistentes e os isolados de carne ovina apresentaram-se mais sensíveis. A CIM foi maior para os Staphylococcus sp. isolados de leite bovino e leite ovino (60µL/mL). Enquanto que para os isolados de carcaça de ovinos e queijo, a CIM foi de 15µL/mL e 30µL/mL respectivamente. A CBM, consequentemente, foi maior para os isolados de leite bovino e leite ovino, sendo de 240µL/mL e 120µL/mL respectivamente. O óleo essencial de Lippia origanoides apresenta atividade antimicrobiana sobre Staphylococcus sp. isolados de alimentos.

The aim of this study was to evaluate the antibacterial activity of the essential oil of Lippia origanoides in relation to Staphylococcus sp. isolated from food of animal origin. For this purpose, we performed the chemical analysis to determine the oil composition, evaluated the bacteria sensibility to ten antibiotics of therapeutic use and determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The chromatographic analysis showed that tymol was the main compound (48.70%) and that carvacrol was present in a small amount (1.14%). In the test of antibiotic susceptibility, 75% of the microorganism isolates were resistant to at least three of the ten antibiotics tested. The Staphylococcus sp isolated from bovine milk was more resistant to the essential oil of Lippia origanoides, and the microorganism isolated from sheep meat was more susceptible to this oil. The Staphylococcus sp. isolated from bovine or sheep milk showed a MIC of 60µL/mL and for those isolated from sheep carcass and cheese the MIC was 15µL/mL and 30µL/mL, respectively. Consequently, the MBC was higher for isolates from cow's (240µL/mL) and sheep's milk (120µL/mL) when compared with other food sources. These results suggest that the essential oil of Lippia origanoides has antimicrobial activity against staphylococcus sp. isolated from food.

Organic fertilization affecting pests and production of Lippia sidoides Cham. (Verbenacea) / Adubação orgânica afetando a ocorrência de pragas e a produção de Óleo essencial em Lippia sidoides Cham. (Verbenacea)

The objective of this paper was to study the effect of four levels of organic fertilization (0, 3, 6 and 9 kg m-2) to produce the essential oil of Lippia sidoides Cham. (Verbenacea) and its pests. A higher number of red mite Tetranychus sp. (Acari: Tetranychiidae) was observed on the abaxial face of the median and basal leaves of L. sidoides plants with eight weeks of age cultivated with 6 kg m-2 of organic fertilization. On the other hand, the smallest number of this mite was noted in control (0 kg m-2). L. sidoides cultivated with 6 kg m-2 of organic fertilization produced a greater quantity of essential oil. The highest number of mealy bug Phenacoccus sp. (Hemiptera: Pseudococcidae) was observed on the apical leaves (both leaf surfaces) of L. sidoides plants with nine and ten weeks of age cultivated with 3 kg m-2 of organic fertilization. No significant effect of the organic fertilization on Aphis gossypii Glover (Hemiptera: Aphididae) was detected. However, a greater number of this aphid and of its predator Scymnus sp. (Coleoptera: Coccinelidae) was observed on the abaxial face of the bottom leaves of L. sidoides plants with eight weeks of age. The dose of organic fertilization recommended for the production of essential oil of L. Sidoides is 6 kg m-2, however, one must pay attention to the fact this dosage favors the attack by Tetranychus sp.. And, when needed, pulverization must always be directed to the lower surface of the leaf.

O objetivo deste trabalho foi avaliar o efeito de quatro níveis de adubação orgânica (0, 3, 6, e 9 kg m-2) na produção de óleo essencial de Lippia sidoides Cham. (Verbenacea) e de suas pragas. Observou-se maior número de ácaro vermelho Tetranychus sp. (Acari: Tetranychiidae) na face inferior das folhas dos terços medianos e basais das plantas de L. sidoides com oito semanas de idade cultivadas com 6 kg m-2 de adubo orgânico. Por outro lado, a menor quantidade deste ácaro foi notada na testemunha (0 kg m-2). L. sidoides cultivada com 6 kg m-2 de adubo orgânico produziu maior quantidade de óleo essencial. Observou-se maior número de cochonilhas Phenacoccus sp. (Hemiptera: Pseudococcidae) nas folhas apicais, sem distinção de face foliar, das plantas de L. sidoides com nove e 10 semanas de idade cultivadas com 3 kg m-2 de adubo orgânico. Não se detectou efeito significativo de adubo orgânico sobre Aphis gossypii Glover (Hemiptera: Aphididae). Contudo, observou-se maior número desse pulgão bem como de seu predador Scymnus sp. (Coleoptera: Coccinelidae) nas faces abaxiais das folhas basais das plantas de L. sidoides com oito semanas de idade. A dose de adubo orgânico recomendada para produção de óleo essencial de L. sidoides é de 6 kg m-2. Contudo, essa dosagem favorece o ataque de Tetranychus sp. e, quando necessário, deve-se dirigir a pulverização sempre para a face inferior da folha, local preferencial de ataque dos artrópodes.

Estudo do sistema de reprodução da fava-d'anta (Dimorphandra mollis Benth. ) / Determination of the reproductive system of fava-d'anta (Dimorphandra mollis Benth. )

Entre as plantas nativas de uso medicinal do Cerrado brasileiro encontra-se a fava-d'anta (Dimorphandra mollis Benth) com alto potencial econômico por possuir inúmeras potencialidades medicinais e fitoquímicas. A indústria extrai dos frutos os princípios ativos rutina, quercetina, e ramnose, dentre outros, usados na fabricação de medicamentos e cosméticos, principalmente no exterior. O conhecimento do sistema reprodutivo da espécie é fundamental para sua conservação e manejo. O presente trabalho objetivou determinar as características morfométricas das flores e caracterizar o sistema reprodutivo da D. mollis em área de Cerrado inalterada antropomorficamente, no município de Olhos D'água - MG. Para as características morfométricas, diâmetro da flor, comprimento da flor, do ovário, e da antera, foram utilizadas cinco flores em pré-antese. Para a determinação do sistema reprodutivo utilizou-se a razão pólen:óvulo (P:O), em 40 flores. As flores da D. mollis apresentaram comprimento da flor de 3,00 mm, diâmetro da flor de 2,00 mm, comprimento do óvulo de 2,60 mm, comprimento da antera de 1,57 mm, e o número de óvulos e de anteras foram 20 e 5,8, respectivamente. A razão P:O foi 765,030, sendo que esse índice não é afetado pelas características morfométricas. O sistema reprodutivo da D. mollis foi classificado como alógama facultativa.

Among the native medicinal plants of the Brazilian Cerrado, we can find the fava-d'anta (Dimorphandra mollis Benth) with a high economic potencial due to its numerous possivbilities for medicinal and phytochemical use. The industry extracts form the fruits the active ingredients rutin, quercetin and rhamnose, among others, used to manufacture medications and cosmetic products, especially abroad. Knowing the reproductive system of the species is important for its conservation and management. This study aimed to determine the morphometric characteristics of flowers and characterize the reproductive system of D. mollis in a Cerrado area that was anthropomorphically unchanged, in the municipality of Olhos D'água - MG. For the morphometric characteristics, flower diameter, length of the flower, of the ovary and the anther, five pre-anthesis flowers were used. To determine the reproductive system, the pollen:ovule (P:O) ratio was used in 40 flowers. The D. mollis flowers presented a flower length of 3.00 mm, flower diameter of 2.00 mm, ovule length of 2.60 mm, anthers length of 1.57 mm, and the number of anthers and ovules were 20 and 5.8, respectively. The P:O ratio was 765,030, and this index is not affected by the morphometric characteristics. The reproductive system of D. mollis was classified as facultative allogamous.

O extrativismo da fava d'anta (Dimorphandra mollis Benth. ) na região do Norte de Minas Gerais / Harvest of "fava-d'anta" (Dimorphandra mollis Benth. ) in the northern region of Minas Gerais State, Brazil

A exploração desenfreada dos ecossistemas tropicais, principalmente o Cerrado, tem provocado uma redução nos indivíduos de inúmeras espécies medicinais, levando prejuízos para toda a população. A falta de informações sobre o extrativismo tem dificultado o uso de estratégias eficazes de manejo e conservação das espécies do cerrado. A fava-d'anta é uma dessas espécies nativas que possuem potencial econômico, principalmente devido à rutina, que é usada na fabricação de fármacos e de cosméticos. O objetivo deste estudo foi analisar os aspectos da atividade de coleta da fava-d'anta pelos coletores e comerciantes. Realizou-se entrevista estruturada com 61 extrativistas, sendo 44 coletores e 17 comerciantes em oito municípios do Norte de Minas Gerais. Constatou-se que a maioria dos entrevistados são homens casados, analfabetos ou com a primeira etapa do ensino fundamental. A coleta da fava-d'anta, apesar de pouco rentável, é uma alternativa para os coletores, sendo a renda inferior à dos comerciantes que já estão nesta atividade de compra da fava-d'anta há mais de 10 anos. A faixa etária de adulto e adulto/idoso são as mais representativas. A época de maior produção ocorre entre os meses de abril a julho, a bienalidade da produção leva à mudança do local de extração. Observou-se o auxílio de toda a família na atividade. Utiliza-se como instrumento de coleta o podão, a foice, facões e outras ferramentas que danificam as árvores. A maior dificuldade para os coletores é a secagem e, para os comerciantes, a venda. O plantio ou a produção de mudas não tem sido prática habitual dos entrevistados.

The uncontrolled exploitation of tropical ecosystems, especially Cerrado, has caused a reduction in individuals of many medicinal plant species, causing damage to the entire population. The lack of information about extraction has hindered the use of effective strategies for management and conservation of Cerrado species. "Fava-d'anta" is one of those native species that have economic potential, largely due to rutin, which is used in the preparation of drugs and cosmetics. The aim of this study was to analyze aspects of the activity of "fava-d'anta" harvest by harvesters and traders. We conducted a structured interview with 61 gatherers, 44 harvesters and 17 traders in eight counties in northern Minas Gerais State, Brazil. Most of them are men who are married and illiterate or had just studied the first stage of basic education. Although little profitable, "fava-d'anta" harvest is an alternative for harvesters, who obtain an income lower than that of traders, who in turn have been trading "fava-d'anta" for more than 10 years. The age range of adults and aged/adults are most representative. The period of greatest production is between April and July, and the 2 year production cycle leads to a change in the extraction site. The whole family helps in the extraction. The instruments used for harvest are trimmers, sickles, machetes and other tools that damage the trees. The greatest difficulty for collectors is seed drying and for traders, selling. The planting or the production of seedlings has not been the usual practice of interviewees.

Produção de fitomassa e teor de óleo essencial de folhas de alecrim-pimenta (Lippia sidoides Cham. ) em diferentes espaçamentos de plantio / Phytomass production and essential oil yield of pepper-rosmarin (Lippia sidoides Cham. ) leaves in different planting spacings

O alecrim-pimenta, espécie nativa do nordeste brasileiro, é uma planta medicinal de porte arbustivo, com folhas aromáticas, que possuem óleo essencial rico em timol e carvacrol. Essas substâncias conferem grande importância à planta, uma vez que apresentam atividades farmacológicas comprovadas cientificamente. Desta forma, o estudo das condições de cultivo da espécie é essencial para obtenção de maiores produtividades. O espaçamento entre plantas destaca-se como um dos fatores mais importantes relativos ao cultivo, de forma que a produtividade e o rendimento da cultura são afetados pela densidade de plantas. Dada a necessidade de otimizar técnicas de cultivo do alecrim-pimenta (Lippia sidoides Cham.), objetivou-se avaliar a produção de fitomassa e óleo essencial em quatro espaçamentos de plantio. O trabalho foi realizado em campo, no Instituto de Ciências Agrárias da Universidade Federal de Minas Gerais (ICA/UFMG), no município de Montes Claros/MG. Utilizou-se o delineamento em blocos casualizados, com quatro tratamentos e cinco repetições. Os tratamentos foram definidos pelos espaçamentos de plantio: 1,0 x 0,5 m; 1,0 x 1,0 m; 1,5 x 1,0 m; e fileiras duplas (1,0 x 0,8 x 0,5m), sendo 1,0 m entre fileiras duplas, 0,8 m entre fileiras simples e 0,5 m entre plantas na fileira. Após 150 dias do plantio no campo, foram avaliadas as variáveis produção de fitomassa fresca e seca das folhas, a produção e o teor de óleo essencial. Observou-se que o espaçamento de 1,0 x 0,5 m possibilitou uma maior produção de fitomassa e de óleo essencial, sendo, portanto, o mais indicado para o cultivo do alecrim-pimenta (Lippia sidoides Cham.).

Native to Northeastern Brazil, pepper-rosmarin (Lippia sidoides Cham.) is a shrubby medicinal plant with aromatic leaves and essential oil rich in thymol and carvacrol. These components have great importance to the species since they present scientifically proven pharmacological activities. Thus, the study of cultivation conditions for this species is essential to obtain higher productivity. Spacing between plants is one of the most important factors related to cultivation, since crop productivity and yield are affected by plant density. Based on the need of optimizing pepper-rosmarin cultivation techniques, this work aimed to evaluate the phytomass production and the essential oil yield in four planting spacings. The experiment was carried out under field conditions in the Agricultural Sciences Institute, Federal University of Minas Gerais (ICA/UFMG), Montes Claros Municipality, Minas Gerais State, Brazil. Experimental design was in randomized blocks, with four treatments and five replicates. Treatments consisted of the planting spacings 1.0 x 0.5 m; 1.0 x 1.0 m; 1.5 x 1.0 m; and double rows (1.0 x 0.8 x 0.5 m), with 1.0m between double rows, 0.8m between single rows and 0.5m between plants in the row. After 150 days of planting in the field, leaf fresh and dry phytomass production and essential oil yield were evaluated. The spacing 1.0 x 0.5 m led to higher phytomass production and essential oil yield, being therefore the most recommended for pepper-rosmarin cultivation.

Efeito da época de colheita na produção de fitomassa e rendimento de óleo essencial de alecrim-pimenta (Lippia sidoides Cham. ) / Effect of harvesting time on phytomass production and essential oil yield in "alecrim-pimenta" (Lippia sidoides Cham. )

O objetivo do estudo foi avaliar a massa fresca, massa seca e rendimento de óleo essencial de Lippia sidoides cultivada no Norte de Minas. O delineamento foi em blocos ao acaso, com quatro tratamentos e cinco repetições. Os tratamentos foram constituídos por intervalos de colheita: 120, 180, 240, 300 e 360 dias após o transplantio. Em cada colheita, foram determinados a altura das plantas, o diâmetro da base do caule, o rendimento de matéria fresca de folhas, caule, parte aérea e o rendimento de matéria seca da parte aérea, além do teor e rendimento de óleo essencial por planta. O teor máximo de óleo essencial foi detectado aos 180 dias, enquanto que a produção máxima de matéria seca ocorreu aos 329 dias. A produção de óleo essencial por planta foi 2,34±1,15 g. A produtividade de óleo essencial foi de 124,8 kg ha-1, sendo recomendada a colheita aos 180 dias.

The aim of this study was to evaluate fresh and dry mass, as well as essential oil yield, in Lippia sidoides cultivated in the north of Minas Gerais State, Brazil. The experimental design was in randomized blocks, with five treatments and four replicates. Treatments consisted of the following harvesting intervals: 120, 180, 240, 300 and 360 days after transplanting. Measurements on each harvesting included plant height, stem base diameter, leaf, stem and shoot fresh matter yield, and shoot dry matter yield, besides essential oil content and yield per plant. The highest essential oil content was detected at 180 days, whereas the highest dry matter production was observed at 390 days. Essential oil yield per plant was 2.34±1.15 g and productivity was 124.8 kg ha-1. Thus, harvesting at 180 days is recommended.