Análise comparativa da modulação autonômica cardíaca no repouso e após teste de esforço máximo em indivíduos fisicamente ativos e em praticantes de treinamento físico de sobrecarga de volume e de resistência cardiovascular

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Educação Física, Programa de Pós-Graduação em Educação Física, 2020.O treinamento físico intervalado de alta intensidade foi popularizado na última década, pela modalidade CrossFit®. Tornando-se uma estratégia de promoção para saúde cardiovascular, assim como, o já estabelecido treinamento aeróbio. Porém, são escassos os dados sobre o efeito do CrossFit® nas adaptações autonômicas cardíaca de repouso e recuperação imediatamente após o esforço comparativamente a modalidade de característica aeróbia como triatlo e a indivíduos fisicamente ativos. Objetivos: Verificar a hipótese de diferença entre a resposta cronotrópica e sua variabilidade, baseada na análise da variabilidade de frequência cardíaca (VFC) no repouso (supino e ortostático) e durante os 5 minutos imediatos após o teste de esforço cardiopulmonar máximo em indivíduos fisicamente ativos com praticantes das modalidades de CrossFit® e triatlo. Métodos: 53 homens adultos aparentemente saudáveis foram distribuídos em três grupos: praticantes de treinamento físico sem modalidade esportiva definida, grupo controle - GC: n=15; 30 (25-36) anos e IMC 24 (19-29) kg/m2; praticantes de CrossFit®, grupo resistência - GR: n=15; 33 (26-39) anos e IMC 26 (21-28) kg/m2 e atletas de triatlo, grupo volume – GV: n=23; 33 (27-37) anos e IMC 24 (21-27) kg/m2. Foram submetidos à análise da frequência cardíaca (FC) e de sua variabilidade nas condições de repouso, esforço e recuperação. Resultados: Os grupos apresentaram bradicardia de repouso na posição supina. O GV apresentou menor FC comparativamente ao GC, durante as posições supina e ortostática (p0,05). O GV apresentou maior reserva cronotrópica comparativamente ao GR (p=0,05). Os índices da VFC no final do esforço foram semelhantes entre os grupos (p>0,05). Durante a condição de recuperação, o GR apresentou menor frequência cardíaca de recuperação (FCR) absoluta e relativa comparativamente ao GV a partir do segundo minuto (p<0,05). Os valores do SD1 foram semelhantes entre os GR e GV. O GC apresentou valores reduzidos de SD1 comparativamente ao GV durante 30 segundos, 1 e 3 minutos; e apenas no 1° minuto comparativamente ao GR (p<0,05). O GR apresentou menor valor de SD2 comparativamente ao GV (p<0,05), durante o terceiro minuto da recuperação. O GR apresentou menores valores de DFA α1 comparativamente ao GC a partir de 1 minuto; e entre 2 e 4 minutos da recuperação comparativamente ao GV (p<0,05). Conclusão: Independente do tipo de treinamento físico todos os grupos apresentaram bradicardia no repouso com destaque para maior bradicardia no GV comparativamente ao GC e GR. Durante o esforço os grupos apresentaram comportamento fisiológico normal. Na condição de recuperação imediatamente após o teste cardiopulmonar, a reativação vagal foi semelhante entre o GV e GR e reduzida no GC. Apesar da semelhante reativação vagal entre os GV e GR o GR demonstrou reduzida FCR absoluta e relativa do 2o ao 5o min comparativamente ao GV. Possivelmente a reduzida FCR observada no GR está associada a duradora coativação dos ramos autonômicos cardíacos simpático e parassimpático ao longo dos 5 min de recuperação.High intensity interval physical training has been popularized in the last decade, by the CrossFit®. Becoming a promotion strategy for cardiovascular health, as well as the already established aerobic training. However, there are few data on the effect of CrossFit® on cardiac autonomic adaptations of rest and recovery immediately after effort compared to the aerobic characteristic modality as triathlon and to physically active individuals. Objectives: To verify the hypothesis of difference between the cronototropic response and its variability, based on the analysis of heart rate variability at rest (supine and orthostatic) and during the 5 minutes immediately after the maximal cardiopulmonary effort test in physically active individuals with practitioners CrossFit® and triathlon. Methods: 53 apparently healthy adult men were divided into three groups: physical training practitioners without defined sports modality, control group - CG: n=15; 30 (25-36) years and BMI 24 (19-29) kg/m2; CrossFit® practitioners, resistance group - RG: n=15; 33 (26-39) years and BMI 26 (21-28) kg/m2 and triathlon athletes, volume group - VG: n=23; 33 (27-37) years and BMI 24 (21-27) kg/m2. They were submitted to heart rate (HR) analysis and their variability in resting conditions, effort and recovery. Results: The groups presented resting bradycardia in the supine position. VG presented lower HR when compared to CG, during the supine and orthostatic positions (p<0.05). The VG presented lower value of DFA α1 compared to the CG (p<0.05) during the supine position. The RG presented higher SD1 compared to the CG during the orthostatic position (p<0.05). At the beginning of the exercise, VG presented lower HR compared to the CG and RG (p<0.05). The groups presented similar values of oxygen consumption (VO2) recorded during the anaerobic threshold and HR and VO2 at the peak effort (p>0.05). The VG presented higher chronotropic reserve compared to the RG (p=0.05). HRV indices at the end of the effort were similar among the groups (p>0.05). During the recovery condition, the RG presented lower absolute and relative recovery heart rate (HRR) compared to the VG from the second minute (p<0.05). The values of SD1 were similar between the RG and VG. The CG presented reduced values of SD1 compared to the VG for 30 seconds, 1 and 3 minutes; and only in the 1st minute compared to the RG (p<0.05). The RG presented lower SD2 value compared to VG (p<0.05) during the third minute of recovery. The RG presented lower values of DFA α1 compared to the CG from 1 minute; and between 2 and 4 minutes of recovery compared to GV (p<0.05). Conclusion: Regardless of the type of physical training, all groups presented bradycardia at rest, with emphasis on greater bradycardia in VG compared to CG and RG. During effort, the groups presented normal physiological behavior. In the recovery condition immediately after cardiopulmonary testing, vagal reactivation was similar between VG and RG and reduced in CG. Despite the similar vagal reactivation between VG and RG, the RG showed reduced absolute and relative HRR from the 2nd to the 5th min compared to the VG. Possibly the reduced HRR observed in the RG is associated with the long-term coactivation of the sympathetic and parasympathetic cardiac autonomic branches over the 5 min of recovery

Estudo teórico da estrutura eletrônica e da dinâmica induzida por lasers da molécula de HCl

Potential energy and dipole moment curves for the HCl molecule were computed. Calculations were performed at different levels of theory (DFT, MRCI). Spectroscopic properties are reported and compared with experimental data, for validating the theoretical approaches. Interaction of infrared radiation with HCl is simulated using the wave packet formalism. The quantum control model for population dynamics of the vibrational levels, based on pi-pulse theory, is applied. The results demonstrate that wavepackets with specific composition can be built with short infrared laser pulses and provide the basis for studies of H + HCl collision dynamics with infrared laser excitation

Structural and mechanical properties of Ti–Si–C–ON for biomedical applications

Ti–Si–C–ON films were deposited by DC reactive magnetron sputtering using different partial pressure of oxygen (pO2) and nitrogen (pN2) ratio. Compositional analysis revealed the existence of two different growth zones for the films; one zone deposited under low pO2/pN2 and another zone deposited under high pO2/pN2. The films produced under low pO2/pN2 were deposited at a lower rate and presented a fcc structure, as well as, dense and featureless morphologies. The films deposited with high pO2/pN2, consequently higher oxygen content, were deposited at a higher rate and developed an amorphous structure. The structural changes are consistent with the hardness and Young's modulus evolution, as seen by the significant reduction of the hardness and influence on the Young's modulus by increasing pO2/pN2

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Unidad de excelencia María de Maeztu CEX2019-000940-MAim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

Estimating the global conservation status of more than 15,000 Amazonian tree species

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

AimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (&gt;66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R$^{2}$ = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R$^{2}$ = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution