THE INFLUENCE OF SWIMMING VELOCITY ON THE KINEMATIC CHARACTERISTICS OF BACKSTROKE SWIMMING

Under standard workout conditions, swimmers spend most of their time swimming at rates significantly lower than racing speed. Specificity of training is not just a metabolic problem, but also a technical and a kinesiological one. The purpose of this study was to determine to what extent swimming the backstroke at different speeds implies a change in the stroke pattern and in the kinematics of the propulsive movements. We also studied the technical characteristics associated with performance in short distance efforts. A third aim of this study was to compare the intra-cycle velocity variation of the center of gravity of the body to the intra-cycle velocity variation of the hip point. Seven well-trained male swimmers participated in this study (age: 14.71±0.76 years, height: 1.74±0.39 m, body mass: 63.14±5.52 kg, %FAT: 15.40±1.81). Each subject performed 3 x 50 m backstroke repeats with 15 min of rest at a velocity corresponding to 90% (v90), 95% (v95) and 100% (vmax) of best performance in the 50 m backstroke. The swimmers were filmed on the sagittal plane, underwater and above the water, with synchronized cameras (60 Hz). Images were mixed and then digitized for further analysis using the APAS system. Peak mean horizontal velocities of the hand occurred during the upsweep at v90 and v95 and during the finish/exit at vmax. Total stroke duration decreased from v90 to v100 due to the shorter duration of the downsweep, the final downsweep and the finish/exit, but the relative duration of the phases did not show any significant changes. Increasing velocity caused an increase in the distance between point of entry into the water and point of exit of the hand from the water, but mean horizontal pulling length decreased. Swimming velocity at sub-maximal paces correlated well to mean body velocity at the upsweep, but at vmax, the highest association was to body velocity at the final downsweep. Maximal velocity in the 50 m backstroke was inversely correlated to the range of intra-cycle velocity variations of the body center of gravity. This parameter showed a poor individual correlation to the hip velocity variation (r=0.58 ± 0.18). The correlation between the coefficient of variation of the hip and the center of gravity intra-cycle velocities had, on the contrary, a high significance. Movement of temporal and spatial structures seem to vary little with velocity changes in swimmers who have attained a good stabilization of motor execution. In fast swimming, nevertheless, swimmers apparently achieve a greater anterioposterior stabilization of the hand, which may indicate more pronounced lift oriented sculling actions, and performance becomes more dependent on the final portion of the underwater path. The variation of the mean velocity of the hip cannot be used for quantification of the changes of body velocity from phase to phase, but a coefficient of variation (SD . mean-1 . 100) of intra-cycle hip velocity seems to be an adequate indicator of the intra-cycle velocity variation of the body center of gravity

POTENTIAL OF ENTOMOPATHOGENIC NEMATODES FOR CONTROL OF THE ERVA-MATE PEST HEDYPATHES BETULINUS (KLUG, 1825) (COLEOPTERA: CERAMBYCIDAE)

The intensive exploitation of “erva mate” (Ilex paraguariensis St. Hil.) (Aquifoliaceae) has favored the emergence of pests, including Hedypathes betulinus. We evaluated 18 isolates of entomopathogenic nematodes in the Steinernema and Heterorhabditis genera for control of H. betulinus adults, and tested nematode in-vivo replication capacity in Galleria mellonella L. (Lepidoptera: Pyralidae) larvae. We also evaluated the effect of adjuvants for foliar application, and the efficiency of nematode isolates selected in erva mate seedlings in the greenhouse via application to soil and plant shoots. The PI and CB40 isolates showed the hgh virulence (92.5% insect mortality by both). The PI isolate showed low productivity in G. mellonella larvae, thus only CB40 was used in subsequent tests. Only emulsified vegetable oil adjuvant was compatible with nematodes. Soil application of nematodes proved ineffective; however, shoot application on erva mate seedlings showed significant mortality (82.5%) after exposure to the CB40 isolate without adjuvant

Caso prático – manifestações no COMETLIS

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Harvest timing and potassium doses on post-harvest quality of dwarf-green coconut water

Coconut is an expressive culture in tropical climate regions and its yield and fruit quality is directly linked to several factors, such as climatic conditions, fertilizer management, harvesting fruits period and other factors. Aiming to evaluate post-harvest of irrigated green dwarf coconut water quality due to potassium doses and different harvesting time, an experiment was carried out at the Federal Rural University of the Semi-Arid - UFERSA from January to November 2015. The experimental design was split-plot randomized blocks. Plots were 5 potassium doses (0, 150, 300, 450 and 600 g plant-1) and the subplots 4 harvesting time of fruits (5, 6, 7 and 8 months after the opening of the inflorescence), 4 blocks and 2 plants for a total of 40 treatment plants. The experimental area consisted of coconut trees of green dwarf variety with four years old. Were evaluated the titratable acidity, soluble solids, ratio, electrical conductivity, pH, total sugar and levels of potassium, calcium, magnesium, sodium and chlorine from coconut water. Under the conditions studied, higher doses of potassium decreased qualitative characteristics of coconut water, the absence of potassium fertilization coconut trees had better results. The optimal harvest time is between 6 and 7 months old.O coco é uma cultura expressiva em regiões de clima tropical e seu rendimento e qualidade dos frutos estão diretamente ligados a diversos fatores, como condições climáticas, manejo de fertilizantes, período de colheita dos frutos e outros fatores. Com o objetivo de avaliar a qualidade pós-colheita de água de coco anã verde irrigada por doses de potássio e diferentes épocas de colheita, foi realizado um experimento na Universidade Federal Rural do Semiárido - UFERSA de janeiro a novembro de 2015. O delineamento experimental foi dividido - traçar blocos aleatórios. Parcelas foram 5 doses de potássio (0, 150, 300, 450 e 600 g planta-1) e as subparcelas 4 tempo de colheita dos frutos (5, 6, 7 e 8 meses após a abertura da inflorescência), 4 blocos e 2 plantas para um total de 40 estações de tratamento. A área experimental foi constituída por coqueiros da variedade anã verde com quatro anos de idade. Foram avaliados a acidez titulável, sólidos solúveis, razão, condutividade elétrica, pH, teor de açúcar total e níveis de potássio, cálcio, magnésio, sódio e cloro da água de coco. Nas condições estudadas, doses mais elevadas de potássio diminuíram as características qualitativas da água de coco, a ausência de adubação potássica nos coqueiros teve melhores resultados. O tempo ótimo de colheita é entre 6 e 7 meses de idad

Trindade, Sara Dias; Carvalho, Joaquim Ramos de (2019). História, tecnologias digitais e mobile learning: ensinar história na era digital [recensão]

Recensão a: Trindade, Sara Dias; Carvalho, Joaquim Ramos de (2019). História, tecnologias digitais e mobile learning: ensinar história na era digital. Coimbra: Imprensa da Universidade de Coimbra

Phenology and production of guava tree cv. “Paluma” pruned at different seasons in Mossoro – RN, Brazil.

The pruning allows fruit harvest in different periods, according to the grower decision, being economically viable. The harvest can be scheduled according to the agronomical traits and due to the market price. The experiment was conducted in the didactic orchard of the Federal University of the Semi-Arid Region (UFERSA), from April 2013 to December 2014, in the municipality of Mossoro-RN. It was carried out in a randomized block design, with treatments arranged in a split-plot, which were composed by pruning periods, conducted in April (2013), November (2013) and July (2014). The subplots consisted of pruning intensities (short, medium and long); with four repetitions, where the experimental unit consisted of two plants that was pruned with 8 marked branches. From pruning to harvest, the the following botanical characteristics were evaluated in the marked branches: number of emitted sprouts by branches pruned at the day 15th (NBE); number of established branches by branches pruned at the day 50th (NRE); number of productive branches (NRP); vegetative number (VRN) and the total number of fruits (NFT). The evaluated characteristics presented a significant effect. The long pruning resulted in a higher number of fruits for all evaluated seasons. The best months for pruning was November and July. The guava tree ‘Paluma’ cycle, from pruning to harvest can vary according to the period of pruning, with 132 days in July and 150 days in April.The pruning allows fruit harvest in different periods, according to the grower decision, being economically viable. The harvest can be scheduled according to the agronomical traits and due to the market price. The experiment was conducted in the didactic orchard of the Federal University of the Semi-Arid Region (UFERSA), from April 2013 to December 2014, in the municipality of Mossoro-RN. It was carried out in a randomized block design, with treatments arranged in a split-plot, which were composed by pruning periods, conducted in April (2013), November (2013) and July (2014). The subplots consisted of pruning intensities (short, medium and long); with four repetitions, where the experimental unit consisted of two plants that was pruned with 8 marked branches. From pruning to harvest, the the following botanical characteristics were evaluated in the marked branches: number of emitted sprouts by branches pruned at the day 15th (NBE); number of established branches by branches pruned at the day 50th (NRE); number of productive branches (NRP); vegetative number (VRN) and the total number of fruits (NFT). The evaluated characteristics presented a significant effect. The long pruning resulted in a higher number of fruits for all evaluated seasons. The best months for pruning was November and July. The guava tree ‘Paluma’ cycle, from pruning to harvest can vary according to the period of pruning, with 132 days in July and 150 days in April. durando entre 132 em julho a 150 dias em abril. &nbsp

Comparative analysis of impacted upper canines : panoramic radiograph vs cone beam computed tomography

Background: The use of CBCT exam in the study of IMC is not new. However, it?s still not known in what specific aspects CBCT exam shows a better result than then conventional exams. The aim of this study was to compare and conclude in what way the opinion regarding upper canine impaction differed when observing a panoramic image compared to the observation of a set of CBCT reconstructions. Materials and Methods: Twenty patients (10 males and 10 females) with a total of 28 impacted maxillary canines were identified from the database of the Department of Dentistry, Faculty of Medicine, University of Coimbra. For each canine, two different images were available: a panoramic image and a set of CBCT reconstructions. After a random distribution of both groups images, nine orthodontists completed a questionnaire where they were asked to evaluate ten different questions regarding canine impaction. Statistic analysis was performed using Cronbach?s alpha statistics, Kappa statistics and McNemar test, considering p<0,05 statistically significant. Results: This study showed differences between the two images regarding tooth position. A statistical significant poor agreement was found between the two methods for the mesio-distal position of the apex (k=0,388, p<0,001) and for the labio-palatal tip cusp position (k=0,035, p=0,114). The adjacent root resorption showed a poor and very poor agreement between the two methods. Every other items were scored with an agreement between modalities ranging from moderate to strong. Conclusions: The analyses of panoramic images versus CBCT images reconstructions provided different information regarding tooth position (especially concerning the mesio-distal apex position and the labio-palatal cusp position) but also in the assessment of root resorption. Further investigation should be done to determine in what cases CBCT exam has a clear advantage over conventional 2D exams, justifying its us

SOFT POWER: ESTRATÉGIA DE DIFUSÃO CULTURAL NORTE-AMERICANO

O presente trabalho apresentará alguns conceitos que há para o termo globalização, definirá o que é Soft Power à luz das idéias de Joseph Nye e demonstrará como o processo de globalização intensificou a difusão da cultura norte-americana através do uso do poder brando no cenário mundial