Response Interruption and Redirection (RIRD) was compared to no-interaction, continuous neutral sound, and contingent neutral sound in order to determine the mechanism by which RIRD functions to suppress vocal stereotypy in children diagnosed with autism spectrum disorder. A neutral sound was determined through the use of a preference assessment of various sounds. Use of a neutral sound did not suppress vocal stereotypy in participants. Manipulating the amount of time with a sound playing did not have an effect on vocal stereotypy either. These results suggest that it is unlikely that RIRD suppresses vocal stereotypy through an extinction-like effect. Rather, it is more likely that RIRD suppresses vocal stereotypy through a punishment-like effect.

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Previous work on rigid splitter plates in the wake of a bluff body has shown that the primary vortex shedding can be suppressed for sufficiently long splitter plates. In the present work, we study the problem of a flexible splitter plate in the wake of a circular cylinder. In this case, the splitter plate can deform due to the fluid forces acting on it, and hence the communication between the two sides of the wake is not totally disrupted like in the rigid splitter plate case. In particular, we study two kinds of flexible splitter plates. In the first case, the splitter plate is rigid but is flexibly mounted (hinged) to the cylinder, while in the second case, the entire splitter plate is flexible. We are interested in both the dynamics of the splitter plate, if they do vibrate at all, and in the wake dynamics downstream of the flexible splitter plates. The main parameters in the problem are the splitter plate length (L) to cylinder diameter (D) ratio, the relative mass of the plate, the Reynolds number, and the stiffness and internal damping associated with the flexible plate. In our study, we investigate this problem in the limit where the stiffness and internal damping of the plate are negligible and hence are not parameters of interest. For the hinged-rigid splitter plate case, experiments show that the splitter plate oscillations increase with Reynolds numbers at low values of Re, and are found to reach a saturation amplitude level at higher Re. This type of saturation amplitude level that appears to continue indefinitely with Re, appears to be related to the fact that there is no structural restoring force in this case, and has been seen previously for elastically-mounted cylinders with no restoring force. In the present case, the saturation tip amplitude level can be up to 0.45D,where D is the cylinder diameter. For this hinged-rigid splitter plate case, it is found that the splitter plate length to cylinder diameter (L/D) ratio is crucial in determining the character and magnitude of the oscillations. For small splitter plate lengths (L/D ≤ 3.0), the oscillations appear to be nearly periodic with tip amplitudes of about 0.45D nearly independent of L/D. The non-dimensional oscillation frequencies (fD/U ) on the other hand are found to continuously vary with L/D from fD/U ≈ 0.2at L/D =1 to fD/U ≈ 0.1 at L/D = 3. As the splitter plate length is further increased beyond L/D ≥ 4.0, the character of the splitter plate oscillations suddenly changes. The oscillations become aperiodic with much smaller amplitudes. In this long splitter plate regime, the spectra of the oscillations become broadband, and are reminiscent of the change in character of the wake oscillations seen in the earlier fixed-rigid splitter plate case for L/D ≥ 5.0. It appears that the vortex shedding is nearly inhibited for L/D ≥ 4.0 in the present case. This is also supported by measurements of the wake vorticity field from Particle-Image Velocimetry (PIV). The phase-averaged PIV vorticity fields show that the strength of the shed vortices decreases rapidly as the splitter plate length increases. For longer splitter plates, L/D ≥ 4.0, the plate oscillations are no longer periodic, and hence it appears that the wake vortices are not synchronized with the splitter plate motions. For the entirely-flexible splitter plate case, the splitter plate deformations appear to be in the form of a travelling wave. In this case, the tip amplitudes are significantly larger of the order of 1.1D, and the non-dimensional oscillation frequency (fD/U )is close to 0.2, approximately the same as the Strouhal number for the bare cylinder. In sharp contrast to the hinged-rigid splitter plate case, the non-dimensional amplitude and frequency appear to be nearly independent of the normalized splitter plate length (L/D)even up to L/D =7.0. PIV measurements of the wake vorticity field indicates that there appears to be a nearly continuous sheet of vorticity on both sides of the flexible splitter plate, and the vortex sheet sheds and forms distinct vortices only at the trailing edge of the plate. The strength of these shed vortices appears to be close to that of the bare cylinder at similar Re. The results appear to suggest that in this entirely-flexible case, the vortices form at the same frequency and are of the same strength as in the bare cylinder case, but their formation is just pushed further downstream. This would suggest that in this case, the base suction and drag could be lower than the bare cylinder. Further, the formation of vortices further downstream of the body could imply that this type of flexible splitter plate could be useful to suppress vortex-induced vibrations (VIV).

Submitted by (lucia.rodrigues@ufrpe.br) on 2016-08-25T14:43:48Z No. of bitstreams: 1 Hugo Henrique Costa do Nascimento.pdf: 3926222 bytes, checksum: ff626f3f3693af25b6e00e1333bd2dec (MD5) / Made available in DSpace on 2016-08-25T14:43:48Z (GMT). No. of bitstreams: 1 Hugo Henrique Costa do Nascimento.pdf: 3926222 bytes, checksum: ff626f3f3693af25b6e00e1333bd2dec (MD5) Previous issue date: 2013-02-27 / Among the tree species native to Brasil, the jatoba (Hymenaea courbaril L.) has been the subject of several studies addressing its potential in carbon sequestration, as well as restoration of degraded environments. However, the physiological responses on the water stress, salinity and nutritional plants jatoba are practically unknown. In order to clarify some of the relationships between these processes, the present study aimed to evaluate the effects of suppression water, salinity and omission of N, P and K in the physiological behavior of seedlings jatoba. To conduct this work were conducted three experiments in the greenhouse of the Laboratory of Plant Physiology, Department of Biology, Universidade Federal Rural de Pernambuco, Recife, Brazil. Therefore, the plants were propagated from seeds collected in two regions of occurrence of the species, in the Pernambuco State. The first trial addressed the effects of water stress by suppressing irrigation and later irrigation, while for the evaluation of salt stress, we conducted a test checking the deleterious effects of the incremental addition of NaCl (0, 50 and 100 mM), hydroponically, and finally the effects of omission of N, P and K were evaluated in the third trial. In all experiments, the parameters were evaluated for growth, gas exchange, water relations, photosynthetic pigments, quantum efficiency of photosystem II and biochemical aspects by quantification of compatible solutes. The results of this study infers that jatoba seedlings have a tendency to accumulation of photosynthetic pigments and organic solutes, mainly proline as the main features of coping suppression watering. Fact allowing rapid reestablishment of their metabolism after rehydration in the early stage of development. Another fact that should be emphasized is that there is evidence that they bear up to 12 days of drought without compromising your metabolism. Information that may be useful to reforestation programs and producing seedlings of the species. Regarding the behavior versus salinity, it is concluded that the jatobá plants osmotically adjusted, once accumulated organic solutes that promote the increase of leaf turgidity, resulting in the continued growth and stabilization of gas exchange, even after subjection to stress severe salt (100 mM). Among the variables is recommended to evaluate the levels of chloride, sodium and potassium in the leaves, stems and roots for the characterization of the state of tolerance to salinity changes of jatoba. Regarding the behavior of seedlings by omission of N, P and K was observed that N was the most limiting macronutrient development of jatoba plants, suggesting that the nutritional requirement regarding macronutrients of that species obeying the order of decreasing N> P> K. It is hoped that the results obtained in this study may elucidate the main mechanisms used by jatobá to tolerate abiotic stresses and that information is useful for establishing adequate management exploitation of the species, since the ease of obtaining seedlings and its occurrence in areas prone to various environmental stresses, enhance its use in the processes of reclamation and / or reforestation. / Dentre as espécies arbóreas nativas do Brasil, o jatobá (Hymenaea courbaril L.) tem sido alvo de diversos estudos abordando sua potencialidade na fixação de carbono, bem como na recuperação de ambientes degradados. No entanto, as respostas fisiológicas ante os estresses hídrico, salino e nutricional em plantas de jatobá ainda apresentam lacunas a serem esclarecidas. Visando elucidar algumas desses pontos, o presente estudo objetivou avaliar os efeitos da supressão hídrica, salinidade e omissão de N, P e K no comportamento fisiológico de mudas de jatobá. Para a realização desse trabalho foram conduzidos três ensaios em casa de vegetação do Laboratório de Fisiologia Vegetal do Departamento de Biologia da Universidade Federal Rural de Pernambuco, Recife, Brasil. Para a montagem dos experimentos foram utilizadas as mudas obtidas de sementes colhidas em duas regiões de ocorrência da espécie, situadas no Agreste pernambucano. No primeiro ensaio foram avaliados os efeitos do estresse hídrico por meio da supressão de rega e posterior reirrigação; já para a análise do comportamento das mudas sob estresse salino, conduziu-se um ensaio verificando os efeitos deletérios da adição crescente de NaCl (0, 50 e 100 mM), em sistema hidropônico; por fim, os efeitos da omissão de N, P e K foram avaliados no terceiro ensaio. Em todos os experimentos, foram avaliados as variáveis de crescimento, trocas gasosas, relações hídricas, pigmentos fotossintéticos, eficiência quântica do fotossistema II e aspectos bioquímicos pela quantificação de solutos compatíveis. Os resultados desta pesquisa permitem inferir que mudas de jatobá acumulam pigmentos fotossintéticos e solutos orgânicos, principalmente a prolina, como as principais características de enfrentamento a supressão de rega. Fatos que possibilitam um rápido reestabelecimento de seu metabolismo após a reidratação na fase inicial do desenvolvimento. Outro fato que merece ser destacado é que há indícios de que as mesmas suportem até 12 dias de estiagem sem comprometer seu metabolismo. Informação que pode ser útil a programas de reflorestamento e produtores de mudas da referida espécie. Quanto ao comportamento ante a salinidade, conclui-se que as plantas de jatobá se ajustaram osmoticamente, uma vez que acumularam solutos orgânicos que promoveram a elevação da turgescência foliar, resultando na continuidade do crescimento e estabilização das trocas gasosas, mesmo após submissão a um estresse salino severo (100 mM). Dentre as variáveis estudadas recomenda-se a avaliação dos teores de cloreto, sódio e potássio nas folhas, caules e raízes para a caracterização do estado de tolerância de mudas de jatobá à salinidade. Em relação ao comportamento das mudas mediante omissão de N, P e K observou-se que o N foi o macronutriente mais limitante ao desenvolvimento de plantas de jatobá, sugerindo que o requerimento nutricional quanto aos macronutrientes da referida espécie obedeça à ordem decrescente de N>P>K. Os resultados obtidos nesta pesquisa indicam os principais mecanismos utilizados pelo jatobá para tolerar estresses abióticos. Essas Informações podem ser úteis para o estabelecimento de um manejo adequado à exploração da espécie, uma vez que a facilidade de obtenção de mudas aliada a ocorrência em áreas propensas a estresses ambientais diversos, potencializam a utilização do jatobá nos processos de recuperação de áreas degradadas e/ou reflorestamentos.