176 research outputs found
Diversidade subgenérica de Brasilonema (Cyanobacteria, Scytonemataceae)
The recently described scytonematoid cyanobacterial genus Brasilonema is known mainly from tropical and subtropical rain forests (Mata Atlântica) of southeastern Brazil, where it occurs in aerophytic wooden, stony and iron substrates. This genus was defined according to both molecular and morphological criteria. The type species B. bromeliae was described from the specialized habitat: it grows in phytothelmes, epiphytic on both living and died leaves within the rosettes of large bromeliad plants slightly above or in the zone of the water level. The genus Brasilonema is evidently widely distributed in coastal forests of São Paulo State, where it occurs also in remarkable diversity. According to our results, this genus currently comprises seven taxa, which are distinct by different morphology and ecological characteristics.O gênero scytonematóide de Cyanobacteria, Brasilonema, foi descrito recentemente e é conhecido principalmente de florestas tropicais e subtropicais (Mata Atlântica) da região sudeste do Brasil. Ocorre sobre substratos aerofíticos como madeira, pedra e ferro e foi definido de acordo com critérios moleculares e morfológicos. A espécie-tipo, B. bromeliae, foi coletada em um habitat muito específico: epífita em folhas de bromélias, dentro das rosetas, próximo do nível da água, ou ainda em folhas secas destas plantas. O gênero Brasilonema é amplamente distribuído nas florestas costeiras do Estado de São Paulo, onde ocorre em alta diversidade morfológica. De acordo com nossos resultados, este gênero atualmente compreende sete táxons distintos com base nas diferenças morfológicas e características ecológicas
Simulated hemodynamics in human carotid bifurcation based on Doppler ultrasound data
Background: Atherosclerotic lesions commonly develop at arterial branch sites. Noninvasive carotid artery ultrasound is a well-established and effective method which allows real-time images and measurements of flow velocities. We aimed to develop a methodology for patient-specific computational 3D reconstruction and blood flow simulation based on ultrasound image data.Material and Methods: Subject-specific studies based on the acquisition of a set of longitudinal and sequential cross-sectional ultrasound images and Doppler velocity measurements at common carotid artery (CCA) bifurcation were performed at a university hospital. A developed simulation code of blood flow by the finite element method (FEM) that includes an adequate structured meshing of the common carotid artery bifurcation was used to investigate local flow biomechanics.Results: Hemodynamic simulations of CCA bifurcations for six individuals were analysed. Comparing pairs (Doppler, FEM) of velocity values, Lin's concordance correlation coefficient analysis demonstrated an almost perfect strength of agreement (c = 0.9911), in patients with different degrees of internal carotid artery (ICA) stenosis. Numerical simulations were able to capture areas of low wall shear stress correlated with stagnation zones.Conclusions: Simulated hemodynamic parameters can reproduce the disturbed flow conditions at the bifurcation of CCA and proximal ICA, which play an important role in the development of local atherosclerotic plaques. This novel technology might help to understand the relationship between hemodynamic environment and carotid wall lesions, and have a future impact in carotid stenosis diagnosis and management
Evaluation of mitochondrial activity in spermatozoids after collecting and posthawing in Boer and Alpine goats in autumn and spring
Caprine spermatozoa undergo glycolisis and mitocondrial respiration to keep the necessary
energy balance to their transportation and other cellular functions. An objective test to evaluate
quantitatively and qualitatively mitochondrial activity in caprine spermatozoa was applied in the analysis
of semen samples of 9 bucks from Boer (n=5) and Alpine (n=4) breeds. Samples were collected and
frozen in TRIS medium in two different year seasons. Semen collection was performed using artificial
vagina to obtain 135 ejaculates, which were used to post-collection and post-frozen extended in sildes.
To determine mitochondrial activity, a citochemical procedure developed and validated for HRUDKA
(1987) was used. The technique is based on the enzymatic 3,3-diaminobenzidine (DAB) oxidation,
where the reagent is polymerized and attached to the mitochondrial membrane throughout the spermatic
intermediary piece. A medium level of citochemical activity (IAC) was determined as being 74,37%,
74,37% during Autumn and 77% e 77,75% during Spring for Boer and Alpine breeds, respectively. For
post-collection IAC levels were 85,62% and 85,93 and for post-frozen 66% and 67,25% for Boer and
Alpine breeds, respectively. ANOVA test was used to evaluate breed, post-collection, post-frozen, IAC
rates and year season parameters. Differences were not noticed for breed, IAC rates and year season.
Nonetheless, there was a significant effect among samples for post-collection and post-frozen analysis
(POs espermatozóides caprinos realizam a respiração mitocondrial, mantendo um balanço energético
necessário para o transporte e as demais funções celulares. Um teste objetivo de avaliação quantitativa e
qualitativa da atividade mitocondrial em espermatozóides caprinos foi aplicado no sêmen de nove reprodutores
das raças Boer (n=5) e Alpina (n=4) colhidos e congelados em diluidor TRIS em duas estações. A colheita do
sêmen foi realizada com auxílio da vagina artificial, totalizando 135 ejaculados e foram confeccionados
esfregaços com sêmen pós-colheita e pós-descongelação. Para a determinação da atividade mitocondrial foi
utilizado o procedimento citoquímico desenvolvido e validado por HRUDKA (1987). Esta técnica é baseada
na oxidação da 3,3-diaminobenzidine (DAB) pela enzima em reação em cadeia, onde o reagente é polimerizado
e depositado na bainha mitocondrial ao longo da peça intermediária dos espermatozóides. Foi determinado
um índice médio de atividade citoquímica (IAC) de 74,37%, 74,37% no outono, 77% e 77,75% na primavera.
E 85,62% e 85,93 no pós-colheita, 66% e 67,25% pós-descongelação para as raças Boer e Alpina,
respectivamente. As variáveis raças, pós-colheita e pós-descongelação, classes (IAC), e estação foram
estudadas por meio de ANOVA. Não foram observadas diferenças estatísticas para raças, classes, bem
como para as estações. Entretanto, efeito significativo entre as amostras pós-colheita e pós-descongelação
(
Conditional expression of apical membrane antigen 1 in Plasmodium falciparum shows it is required for erythrocyte invasion by merozoites
Malaria is caused by obligate intracellular parasites, of which Plasmodium falciparum is the most lethal species. In humans, P. falciparum merozoites (invasive forms of the parasite) employ a host of parasite proteins to rapidly invade erythrocytes. One of these is the P. falciparum apical membrane antigen 1 (PfAMA1) which forms a complex with rhoptry neck proteins at the tight junction. Here, we have placed the Pfama1 gene under conditional control using dimerizable Cre recombinase (DiCre) in P. falciparum. DiCre‐mediated excision of the loxP‐flanked Pfama1 gene results in approximately 80% decreased expression of the protein within one intraerythrocytic growth cycle. This reduces growth by 40%, due to decreased invasion efficiency characterized by a post‐invasion defect in sealing of the parasitophorous vacuole. These results show that PfAMA1 is an essential protein for merozoite invasion in P. falciparum and either directly or indirectly plays a role in resealing of the red blood cell at the posterior end of the invasion event.Alan Yap, Mauro F. Azevedo, Paul R. Gilson, Greta E. Weiss, Matthew T. O’Neill, Danny W. Wilson, Brendan S. Crabb and Alan F. Cowma
Scarabaeinae (Coleoptera: Scarabaeidae) of a rupestrian field at Cafuringa, Distrito Federal, Brazil: commented list of species
The future problem solving program international: an intervention to promote creative skills in portuguese adolescents
The Future Problem Solving Program International (FPSPI) is an internationally applied educational
program that involves young people. Its theoretical foundation is both the Creative Problem Solving
Model and the Futurist Thinking. It aims to promote creative and critical thinking through a futurist
approach to problems. This study intended to analyze the effects of the program on creative skills evaluated
by the Torrance Tests of Creative Thinking (Figural Version). The participants’ perceptions of the
efficacy of the program were also assessed. This intervention was carried out with 131 adolescents over
a period of 7 months in an extra-curricular context. The evaluation of the program takes into account
periods both before and after interventions, using similar experimental and control groups. The results
showed significant statistical differences for the all skills studied and very positive perceptions of the
efficacy of FPSPI. Two significant gender differences in creative performance were also found. The
results are described and discussed in order to promote awareness for future research concerning this program(undefined)info:eu-repo/semantics/publishedVersio
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