Statistical translation invariance protects a topological insulator from interactions

We investigate the effect of interactions on the stability of a disordered, two-dimensional topological insulator realized as an array of nanowires or chains of magnetic atoms on a superconducting substrate. The Majorana zero-energy modes present at the ends of the wires overlap, forming a dispersive edge mode with thermal conductance determined by the central charge $c$ of the low-energy effective field theory of the edge. We show numerically that, in the presence of disorder, the $c=1/2$ Majorana edge mode remains delocalized up to extremely strong attractive interactions, while repulsive interactions drive a transition to a $c=3/2$ edge phase localized by disorder. The absence of localization for strong attractive interactions is explained by a self-duality symmetry of the statistical ensemble of disorder configurations and of the edge interactions, originating from translation invariance on the length scale of the underlying mesoscopic array.Comment: 5+2 pages, 8 figure

Postural Control in Preschool Children with Developmental Coordination Disorder, in Sitting Position During a Functional Task

The developmental coordination disorder is a motor disorder that affects 5 to 6% of children at school-age. The postural control deficit is one of the most prevalent problems affecting 73 to 87% of these children. The present research aims to analyze and compare postural control in probable (p-DCD) and at- risk of developmental coordination disorder children and in typical children in a sitting position during a functional task. p-DCD children were tendentially less recurrent, less periodic, simpler and more regular. These children oscillated more and faster in conditions with visual information; with a visual focus they had more stability and oscillated less and slowler campared to the baseline; without visual information they reduced their oscillations and velocity and become less recurrent, periodic, stable and simpler, possibly freenzing more degrees of freedom in order to respond to absence of external information. p-DCD seem to be more dependent on external stimulus like visual information to auto organize their own balance. The greater the task’s complexity, the lesser and slower their oscillations were but also more recurrent and periodic. Despite oscillating, more and faster in all conditions and being tendentially more recurrent and periodic, in risk children revealed a behaviour pattern similar to typical in both variables. p-DCD, at-risk and typical children reveal the same manner of action without visual information, less and slower oscillations. Most likely, the problem with p-DCD is not in motor control, but on perception-action cycles’ effectivness; and, where stimulation must be focused.info:eu-repo/semantics/publishedVersio

Exploratory study on maturation and competition level in young karate practitioners

Emparelhar crianças propicia sucesso e reduz lesões no desporto. Apesar das diferenças de maturação entre crianças, a idade cronológica mantém-se o principal critério para equalizar os níveis de competição, mas com uma eficiência limitada. No entanto, no karaté, o peso também é considerado. Fomos verificar se existe associação entre a idade cronológica e os indicadores maturacionais e, encontrar modelos simples que permitam colocar em reflexão novas formas de avaliação da maturação. Foram recolhidos dados em 54 jovens praticantes de karaté (idade: 12,67 ± 2,49 anos; experiência: 4,99 ± 2,44 anos; altura: 150,45 ± 15,25cm; peso: 43,09 ± 14,17 kg, 20 raparigas). A idade correlacionou-se significativamente com auto-observação da maturação sexual (rho = 0,838; p < 0,01), e foi possível encontrar modelos de regressão simples que têm uma explicação moderada na maturação, apenas utilizando variáveis de medição simples, tal como a altura, o peso e o perímetro do braço. Estes resultados devem levar as entidades competentes a refletir acerca do modo de emparelhamento dos atletas nas competições de uma forma justa em termos de maturação.Paring children improve the chance for success and reduce injury in sport. Despite the maturity differences between children, chronological age remains the main criterion to equalize competition levels, but with limited efficiency. However, in Karate, weight is also considered. We went to investigate the association between chronological age and maturational indicators and find simple models to put on reflection new ways to assess the maturity. Data were collected in 54 young Karate practitioners (age: 12.67 ± 2.49 years, experience: 4.99 ± 2.44 years, height: 150.45 ± 15.25 cm, weight: 43.09 ± 14, 17 kg, 20 girls). Age correlated significantly with self-observation of sexual maturation (rho = 0.838; p < 0.01), and it was possible to find simple regression models that have a moderate explanation in maturation, using only simple measurable variables such as the height, weight and arm circumference. These results should lead the competent entities to reflect on the way of pairing of the athletes in the competitions, in a fair way in terms of maturation.info:eu-repo/semantics/publishedVersio

Novel functions for Rab GTPases in multiple aspects of tumour progression

Rab GTPases are master regulators of intracellular trafficking and, in recent years, their role in the control of different aspects of tumour progression has emerged. In the present review, we show that Rab GTPases are disregulated in many cancers and have central roles in tumour cell migration, invasion, proliferation, communication with stromal cells and the development of drug resistance. As a consequence, Rab proteins may be novel potential candidates for the development of anticancer drugs and, in this context, the preliminary results obtained with an inhibitor of Rab function are also discussed

Effect of Slow Abdominal Breathing Technique on Heart Rate Variability in Male Smokers

Cigarette smoking is one of the highest contributors to the risk of cardiovascular diseases. The aim of the study was to verify the effect of a breathing technique on cardiac autonomic function in long-term male smoker subjects, by short-term heart rate variability analysis. The effect of a breathing technique on heart rate variability, in five long-term male smokers was analyzed. For almost all participants in this study, paced and predominantly abdominal breathing was beneficial, because it afforded greater asymmetry in short-term heart rate variability, as expressed by Poincaré plots, reinforced by significantly higher shortterm variability, long-term variability, root mean square of successive differences, differences of successive intervals greater than 50ms, and Approximate Entropy. An easily learned breathing technique, which is inexpensive and non-intrusive, can help smokers to momentarily remedy the nefarious cardiac effects of their smoking habit.info:eu-repo/semantics/publishedVersio

Composição química e actividade antioxidante das folhas internas da couve tronchuda

A couve tronchuda (Brassica oleracea L. var. costata DC) é uma das couves mais consumidas pelos portugueses, especialmente durante o Inverno, apresentando as folhas (internas e externas) diferenças organolépticas marcadas. No presente trabalho procedeu-se à caracterização química das folhas internas de couve tronchuda, através da identificação e quantificação dos compostos fenólicos e dos ácidos orgânicos que as compõem e avaliou-se o seu potencial antioxidante. Foram identificados e quantificados, por HPLC-DAD-ESI-MS e HPLC/DAD, respectivamente, 17 compostos fenólicos: quercetina 3-O-soforósido-7-O-glucósido, ácido 3-p-cumaroilquínico, campferol 3-O-soforósido-7-O-glucósido, campferol 3-O-(cafeoil)-soforósido-7-O-glucósido, ácido sinapoilglucósido, campferol 3-O-(sinapoil)-soforósido-7-O-glucósido, campferol 3-O-(feruloil)-soforósido-7-O-glucósido, campferol 3-O-(p-cumaroil)-soforósido-7-O-glucósido, ácido 4-p-cumaroilquínico, ácido sinápico, campferol 3-O-soforósido, 3 isómeros de 1,2-di-sinapoilgentiobiose, 1-sinapoil-2-feruloilgentiobiose, 1,2,2-tri-sinapoilgentiobiose e 1,2’-di-sinapoil-2-feruloilgentiobiose. Foram também identificados e quantificados, por HPLC/UV, sete ácidos orgânicos (ácidos aconítico, cítrico, ascórbico, málico, quínico, chiquímico e fumárico). A actividade antioxidante do extracto aquoso foi aferida pela capacidade para interceptar o radical DPPH e espécies reactivas de oxigénio (radicais superóxido e hidroxilo e ácido hipocloroso), tendo revelado grande efeito protector

Chemical and antioxidative assessment of dietary turnip (Brassica rapa var. rapa L.)

The phenolic compounds and organic acids of turnip (Brassica rapa var. rapa L.) edible parts (leaves and stems, flower buds and roots) were determined by HPLC–DAD and HPLC–UV, respectively. The results revealed a profile composed of 14 phenolics (3-p-coumaroylquinic, caffeic, ferulic and sinapic acids, kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol 3-O-sophoroside-7-O-sophoroside, kaempferol 3-O-(feruloyl/caffeoyl)-sophoroside-7-O-glucoside, kaempferol 3,7-O-diglucoside, isorhamnetin 3,7-O-diglucoside, kaempferol 3-O-sophoroside, 1,2-disinapoylgentiobiose, 1,20-disinapoyl-2-feruloylgentiobiose, kaempferol 3-O-glucoside and isorhamnetin 3-O-glucoside) and six organic acids (aconitic, citric, ketoglutaric, malic, shikimic and fumaric acids). The quantification of the identified compounds showed kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol 3-O-(feruloyl/caffeoyl)-sophoroside-7-O-glucoside, isorhamnetin 3,7-O-diglucoside and isorhamnetin 3-O-glucoside as the main phenolics, and malic acid as the organic acid present in highest amounts. A screening of the antioxidative potential was also performed by means of the DPPH radical scavenging assay. Turnip flower buds exhibited the strongest antioxidant capacity

Melanosomes at a glance

Melanosomes, the pigment granules that provide tissues with colour and photoprotection, are the cellular site of synthesis, storage and transport of melanin pigments. They are synthesised in mammalian skin melanocytes, in choroidal melanocytes and retinal pigment epithelial (RPE) cells in the eye, and in melanophores (a class of pigment-containing cells) in lower vertebrates. The precise fate and functions of melanosomes vary according to cell type – epidermal melanocytes supply neighbouring keratinocytes with melanosomes, which results in the pigmentation of skin and hair, whereas pigment granules are retained intracellularly in RPE cells and choroidal melanocytes. In lower vertebrates, the reversible aggregation and dispersion of melanosomes throughout the melanophore enables rapid colour change and adaptation to the environment