Equilíbrio estático e dinâmico no indivíduo com espondilite anquilosante: revisão da literatura

Com o objetivo de analisar as alterações musculoesqueléticas dos indivíduos com espondilite anquilosante (EA) e suas repercussões sobre o controle postural, realizou-se uma revisão bibliográfica nas bases de dados da BIREME e EBSCO HOTS e no site Pubmed com as palavras-chave: "ankylosing spondylitis", "postural balance" e "posture". Foram selecionados artigos envolvendo seres humanos e que analisavam o controle postural e a biomecânica dos indivíduos com EA, nos idiomas inglês e português, publicados no período entre 1999 e 2010. Do total de artigos encontrados, apenas quatro preencheram os requisitos. Desses, três compararam os resultados de pacientes com EA com os dados obtidos de indivíduos saudáveis, e um analisou apenas indivíduos com EA. Nenhum artigo continha o mesmo método de análise postural. Para avaliação do equilíbrio foram utilizadas a Escala de Equilíbrio de Berg, a Plataforma de Força e a Magnometria. Os principais desvios posturais encontrados foram aumento da cifose torácica e flexão do quadril, que levam a uma anteriorização do centro de gravidade corporal, apresentando flexão do joelho e plantiflexão do tornozelo como compensação para manter o equilíbrio. Apenas um autor encontrou piora do equilíbrio funcional nos sujeitos com EA. Todos os métodos de avaliação utilizados foram considerados capazes de mensurar o equilíbrio, não havendo uma escala específica para pacientes com EA.

Análise do controle do equilíbrio em surfistas durante a postura ereta

INTRODUÇÃO: O surfe é uma modalidade que tem crescido bastante, aumentando o interesse nas pesquisas interessadas nos aspectos que podem influenciar no desempenho desses atletas, como, por exemplo, lesões, aptidão aeróbia e tempo de reação. Devido ao ambiente em constante mudança e de alta instabilidade exigido na prática do surfe, é necessário que os surfistas desenvolvam habilidades neuromusculares (agilidade, equilíbrio, força muscular e flexibilidade) para obter um melhor desempenho nesta atividade esportiva. No entanto, ainda são escassos os trabalhos científicos que se preocupam em investigar tais capacidades motoras em surfistas. OBJETIVO: O objetivo deste estudo foi avaliar o controle do equilíbrio em surfistas amadores em relação aos praticantes de outras atividades físicas. MÉTODOS: Os participantes permaneceram sobre uma plataforma de força enquanto realizavam tarefas que envolviam privação visual (olhos abertos ou fechados) e perturbação somatossensorial (superfície firme ou uso de espuma), com covariação das condições experimentais. As seguintes variáveis foram analisadas: velocidade e raiz quadrática média (RMS) do deslocamento do centro de pressão nas direções anteroposterior (AP) e mediolateral (ML). RESULTADOS: Os resultados mostraram que não houve diferença entre os grupos, durante as condições experimentais, isto é, tanto surfistas quanto grupo controle oscilaram mais nas condições de olhos fechados e sobre espuma. CONCLUSÃO: Apesar de o surfe exigir, por parte do esportista, uma grande capacidade em controlar o equilíbrio, os resultados não revelaram relação entre a prática deste esporte e um melhor desempenho no controle do equilíbrio. Porém, devemos considerar o reduzido tamanho da amostra e o fato de a modalidade exigir um equilíbrio dinâmico, enquanto o estudo avaliou o equilíbrio estático.

Equilíbrio, controle postural e força muscular em idosas osteoporóticas com e sem quedas

Um dos maiores problemas de saúde pública na população idosa são as quedas, agravando-se quando relacionadas à presença de osteoporose. Dentre os vários fatores de risco, destacam-se a diminuição do equilíbrio, controle postural e força muscular. O objetivo deste trabalho foi comparar o equilíbrio, o controle postural e a força muscular em idosas osteoporóticas com e sem quedas referidas no último ano. Foram avaliadas 45 mulheres entre 65 e 85 anos, divididas em dois grupos com base no relato de quedas nos 12 meses anteriores à avaliação: grupo com quedas (GCQ; n=21) e grupo sem quedas (GSQ; n=24). O equilíbrio foi avaliado por meio da escala de equilíbrio de Berg; o controle postural pelo teste clínico modificado de interação sensorial no equilíbrio (mCTSIB), realizado no equipamento Balance Master®; e a força muscular dos flexores e extensores de joelho e dorsiflexores de tornozelo, com dinamômetro EMG System do Brasil®. Foi considerado nível de significância α=0,05. Houve diferença significativa no equilíbrio (p<0,01) e na velocidade de oscilação do Centro de Pressão (CP) durante o teste mCTSIB nas condições olhos fechados superfície estável (p=0,05) e olhos abertos superfície instável (p<0,01), com valores maiores para o GCQ. Os grupos foram semelhantes entre si em relação à força muscular (p>0,05). Nossos resultados indicam que idosas osteoporóticas com histórico de quedas nos últimos 12 meses possuem pior equilíbrio e controle postural em relação às osteoporóticas sem quedas referidas.

Influência da obesidade e da força de preensão palmar no equilíbrio postural estático de idosas ativas

O objetivo deste estudo foi investigar a influência da obesidade e da força de preensão palmar (FPP) no equilíbrio postural estático de idosas ativas nas condições de olhos abertos e fechados. Participaram 31 idosas (16 eutróficas e 15 obesas). A idade média e o Índice de Massa Corpórea (IMC) das eutróficas foram, respectivamente, 68,3±2,7 anos e 23,4±1,6kg/m², e das obesas 69,1±2,7 anos e 33,5±3kg/m². A FPP foi avaliada usando um dinamômetro (JAMAR). O equilíbrio postural estático foi avaliado usando um sistema tridimensional nas condições de olhos abertos (OA) e fechados (OF), durante 90 segundos cada condição. A FPP das idosas eutróficas foi 25,1±4,6kgf e das obesas foi 24,8±5,2kgf, não havendo diferenças significativas. No equilíbrio postural, foram observadas diferenças significativas entre os grupos apenas no deslocamento máximo a-p com AO (p=0,04) e OF (p<0,01), com as idosas obesas apresentando menor deslocamento a-p em relação às eutróficas. Não houve correlação entre o deslocamento máximo a-p com IMC e a FPP. No presente estudo FPP não influenciou o equilíbrio postural estático, enquanto a obesidade foi fator determinante de menor deslocamento ântero-posterior de idosas ativas.

Transposable elements dynamics in taxa with different reproductive strategies or speciation rate

In recent years the advances in genomics allowed to understand the importance of Transposable Elements (TE) in the evolution of eukaryotic genomes. In this thesis I face two aspects of the TE impact on the in the animal kingdom. The first part is a comparison of the dynamics of the TE dynamics in three species of stick-insects of the Genus Bacillus. I produced three random genomic libraries of 200 Kbps for the three parental species of the taxon: a gonochoric population of Bacillus rossius (facultative parthenogenetic), Bacillus grandii (gonochoric) and Bacillus atticus (obligate parthenogenetic). The unisexual taxon Bacillus atticus does not shows dramatic differences in TE total content and activity with respect to Bacillus grandii and Bacillus rossius. This datum does not confirm the trend observed in other animal models in which unisexual taxa tend to repress the activity of TE to escape the extinction by accumulation of harmful mutations. In the second part I tried to add a contribute to the debate initiated in recent years about the possibility that a high TE content is linked to a high rate of speciation. I designed an evolutionary framework to establish the different rate of speciation among two or more taxa, then I compared TE dynamics considering the different rates of speciation. The species dataset comprises: 29 mammals, four birds, two fish and two insects. On the whole the majority of comparisons confirms the expected trend. In particular the amount of species analyzed in Mammalia allowed me to get a statistical support (p<0,05) of the fact that the TE activity of recently mobilized elements is positively related with the rate of speciation.

DEVELOPMENT AND APPLICATIONS OF GENOMIC RESOURCES FOR TWO NORTH AMERICAN HARDWOOD TAXA

Hardwoods comprise about half of the biomass of forestlands in North America and present many uses including economic, ecological and aesthetic functions. Forest trees rely on the genetic variation within tree populations to overcome the many biotic, abiotic, anthropogenic factors which are further worsened by climate change, that threaten their continued survival and functionality. To harness these inherent genetic variations of tree populations, informed knowledge of the genomic resources and techniques, which are currently lacking or very limited, are imperative for forest managers. The current study therefore aimed to develop genomic microsatellite markers for the leguminous tree species, honey locust, Gleditsia triacanthos L. and test their applicability in assessing genetic variation, estimation of gene flow patterns and identification of a full-sib mapping population. We also aimed to test the usefulness of already developed nuclear and gene-based microsatellite markers in delineation of species and taxonomic relationships between four of the taxonomically difficult Section Lobatae species (Quercus coccinea, Q. ellipsoidalis, Q. rubra and Q. velutina. We recorded 100% amplification of G. triacanthos genomic microsatellites developed using Illumina sequencing techniques in a panel of seven unrelated individuals with 14 of these showing high polymorphism and reproducibility. When characterized in 36 natural population samples, we recorded 20 alleles per locus with no indication for null alleles at 13 of the 14 microsatellites. This is the first report of genomic microsatellites for this species. Honey locust trees occur in fragmented populations of abandoned farmlands and pastures and is described as essentially dioecious. Pollen dispersal if the main source of gene flow within and between populations with the ability to offset the effects of random genetic drift. Factors known to influence gene include fragmentation and degree of isolation, which make the patterns gene flow in fragmented populations of honey locust a necessity for their sustainable management. In this follow-up study, we used a subset of nine of the 14 developed gSSRs to estimate gene flow and identify a full-sib mapping population in two isolated fragments of honey locust. Our analyses indicated that the majority of the seedlings (65-100% - at both strict and relaxed assignment thresholds) were sired by pollen from outside the two fragment populations. Only one selfing event was recorded confirming the functional dioeciousness of honey locust and that the seed parents are almost completely outcrossed. From the Butternut Valley, TN population, pollen donor genotypes were reconstructed and used in paternity assignment analyses to identify a relatively large full-sib family comprised of 149 individuals, proving the usefulness of isolated forest fragments in identification of full-sib families. In the Ames Plantation stand, contemporary pollen dispersal followed a fat-tailed exponential-power distribution, an indication of effective gene flow. Our estimate of δ was 4,282.28 m, suggesting that insect pollinators of honey locust disperse pollen over very long distances. The high proportion of pollen influx into our sampled population implies that our fragment population forms part of a large effectively reproducing population. The high tendency of oak species to hybridize while still maintaining their species identity make it difficult to resolve their taxonomic relationships. Oaks of the section Lobatae are famous in this regard and remain unresolved at both morphological and genetic markers. We applied 28 microsatellite markers including outlier loci with potential roles in reproductive isolation and adaptive divergence between species to natural populations of four known interfertile red oaks, Q. coccinea, Q. ellpsoidalis, Q. rubra and Q. velutina. To better resolve the taxonomic relationships in this difficult clade, we assigned individual samples to species, identified hybrids and introgressive forms and reconstructed phylogenetic relationships among the four species after exclusion of genetically intermediate individuals. Genetic assignment analyses identified four distinct species clusters, with Q. rubra most differentiated from the three other species, but also with a comparatively large number of misclassified individuals (7.14%), hybrids (7.14%) and introgressive forms (18.83%) between Q. ellipsoidalis and Q. velutina. After the exclusion of genetically intermediate individuals, Q. ellipsoidalis grouped as sister species to the largely parapatric Q. coccinea with high bootstrap support (91 %). Genetically intermediate forms in a mixed species stand were located proximate to both potential parental species, which supports recent hybridization of Q. velutina with both Q. ellipsoidalis and Q. rubra. Analyses of genome-wide patterns of interspecific differentiation can provide a better understanding of speciation processes and taxonomic relationships in this taxonomically difficult group of red oak species.

Phylogeny and prediction of genetic similarity of Cronobacter and related taxa by multilocus sequence analysis (MLSA)

Multilocus sequence analysis (MLSA) based on recN, rpoA and thdF genes was done on more than 30 species of the family Enterobacteriaceae with a focus on Cronobacter and the related genus Enterobacter. The sequences provide valuable data for phylogenetic, taxonomic and diagnostic purposes. Phylogenetic analysis showed that the genus Cronobacter forms a homogenous cluster related to recently described species of Enterobacter, but distant to other species of this genus. Combining sequence information on all three genes is highly representative for the species' %GC-content used as taxonomic marker. Sequence similarity of the three genes and even of recN alone can be used to extrapolate genetic similarities between species of Enterobacteriaceae. Finally, the rpoA gene sequence, which is the easiest one to determine, provides a powerful diagnostic tool to identify and differentiate species of this family. The comparative analysis gives important insights into the phylogeny and genetic relatedness of the family Enterobacteriaceae and will serve as a basis for further studies and clarifications on the taxonomy of this large and heterogeneous family.

Palynological richness and evenness: insights from the taxa accumulation curve

Palynology provides the opportunity to make inferences on changes in diversity of terrestrial vegetation over long time scales. The often coarse taxonomic level achievable in pollen analysis, differences in pollen production and dispersal, and the lack of pollen source boundaries hamper the application of diversity indices to palynology. Palynological richness, the number of pollen types at a constant pollen count, is the most robust and widely used diversity indicator for pollen data. However, this index is also influenced by the abundance distribution of pollen types in sediments. In particular, where the index is calculated by rarefaction analysis, information on taxonomic richness at low abundance may be lost. Here we explore information that can be extracted from the accumulation of taxa over consecutive samples. The log-transformed taxa accumulation curve can be broken up into linear sections with different slope and intersect parameters, describing the accumulation of new taxa within the section. The breaking points may indicate changes in the species pool or in the abundance of high versus low pollen producers. Testing this concept on three pollen diagrams from different landscapes, we find that the break points in the taxa accumulation curves provide convenient zones for identifying changes in richness and evenness. The linear regressions over consecutive samples can be used to inter- and extrapolate to low or extremely high pollen counts, indicating evenness and richness in taxonomic composition within these zones. An evenness indicator, based on the rank-order-abundance is used to assist in the evaluation of the results and the interpretation of the fossil records. Two central European pollen diagrams show major changes in the taxa accumulation curves for the Lateglacial period and the time of human induced land-use changes, while they do not indicate strong changes in the species pool with the onset of the Holocene. In contrast, a central Swedish pollen diagram shows comparatively little change, but high richness during the early Holocene forest establishment. Evenness and palynological richness are related for most periods in the three diagrams, however, sections before forest establishment and after forest clearance show high evenness, which is not necessarily accompanied by high palynological richness, encouraging efforts to separate the two.

Grassland management intensification weakens the associations among the diversities of multiple plant and animal taxa

Land-use intensification is a key driver of biodiversity change. However, little is known about how it alters relationships between the diversities of different taxonomic groups, which are often correlated due to shared environmental drivers and trophic interactions. Using data from 150 grassland sites, we examined how land-use intensification (increased fertilization, higher livestock densities, and increased mowing frequency) altered correlations between the species richness of 15 plant, invertebrate, and vertebrate taxa. We found that 54% of pairwise correlations between taxonomic groups were significant and positive among all grasslands, while only one was negative. Higher land-use intensity substantially weakened these correlations (35% decrease in r and 43% fewer significant pairwise correlations at high intensity), a pattern which may emerge as a result of biodiversity declines and the breakdown of specialized relationships in these conditions. Nevertheless, some groups (Coleoptera, Heteroptera, Hymenoptera and Orthoptera) were consistently correlated with multidiversity, an aggregate measure of total biodiversity comprised of the standardized diversities of multiple taxa, at both high and low land-use intensity. The form of intensification was also important; increased fertilization and mowing frequency typically weakened plant–plant and plant–primary consumer correlations, whereas grazing intensification did not. This may reflect decreased habitat heterogeneity under mowing and fertilization and increased habitat heterogeneity under grazing. While these results urge caution in using certain taxonomic groups to monitor impacts of agricultural management on biodiversity, they also suggest that the diversities of some groups are reasonably robust indicators of total biodiversity across a range of conditions. Read More: http://www.esajournals.org/doi/10.1890/14-1307.1