600 research outputs found

    Synchronous bursts on scale-free neuronal networks with attractive and repulsive coupling

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    This paper investigates the dependence of synchronization transitions of bursting oscillations on the information transmission delay over scale-free neuronal networks with attractive and repulsive coupling. It is shown that for both types of coupling, the delay always plays a subtle role in either promoting or impairing synchronization. In particular, depending on the inherent oscillation period of individual neurons, regions of irregular and regular propagating excitatory fronts appear intermittently as the delay increases. These delay-induced synchronization transitions are manifested as well-expressed minima in the measure for spatiotemporal synchrony. For attractive coupling, the minima appear at every integer multiple of the average oscillation period, while for the repulsive coupling, they appear at every odd multiple of the half of the average oscillation period. The obtained results are robust to the variations of the dynamics of individual neurons, the system size, and the neuronal firing type. Hence, they can be used to characterize attractively or repulsively coupled scale-free neuronal networks with delays.Comment: 15 pages, 9 figures; accepted for publication in PLoS ONE [related work available at http://arxiv.org/abs/0907.4961 and http://www.matjazperc.com/

    Antioxidant activity and polyphenols from seaweed and Halimeda Halimeda Opuntia monile

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    En este trabajo se estudió la actividad antioxidante de dos especies de algas marinas (H. opuntia y H. monile) mediante el ensayo de atrapamiento de radicales DPPH• y el sistema β-Caroteno-acido linoleico. Adicionalmente a las fracciones de ácidos fenolicos libres, ésteres solubles y ésteres insolubles de ácidos fenólicos se les determinó el contenido en fenoles totales mediante la técnica de Folin-Ciocalteu y posteriormente se identificaron y cuantificaron 8 ácidos fenólicos y cinámicos, resultando el componente mayoritario el ácido salicílico. En los ensayos utilizados se obtuvieron valores altos de actividad antioxidante para las diferentes fracciones. A partir de estos resultados se puede postular que la actividad antioxidante de los extractos polares de estas algas pudiera ser explicada, al menos parcialmente, por la presencia de los ácidos fenólicos y cinámicos. En el caso del alga Halimeda monile, de acuerdo con la literatura consultada, es el primer reporte de la actividad antioxidanteIn this paper, the antioxidant activity displayed by two different green seaweed species (H. opuntia y H. monile) was studied using the β- carotene/ linoleic acid and the DPPH• scavenging.systems as different experimental in vitro antioxidant assessment models. Polar seaweed fractions containing free phenolic acids, soluble esters and insoluble esters of phenolic acids were chemically characterized in terms of their phenolic content and composition. In that direction, 8 phenolic acids were identified and quantified, and salycilic acid was shown to be the majoritary compound on the fractions from both species. In addition, the polar fractions were proved to exert antioxidant activity in the two used experimental systems with considerably low values of CI50. Thus, in view of these findings, the antioxidant activity of these polar Halimeda spp. extracts could be supported and at least partially related to the presence of phenolic acids. In case of Halimeda monile this is, at least to the extend of our knowledge, the first report of such biological activity

    4Pipe4-A 454 data analysis pipeline for SNP detection in datasets with no reference sequence or strain information

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    This work was fully supported by projects SOBREIRO/0036/2009 (under the framework of the Cork Oak ESTs Consortium), PTDC/BIA-BEC/098783/2008 and PTDC/AGR-GPL/119943/2010 from Fundação para a Ciência e Tecnologia (FCT) – Portugal. F. Pina-Martins was funded by FCT grant SFRH/BD/51411/2011, under the PhD program “Biology and Ecology of Global Changes”, Univ. Aveiro & Univ. Lisbon, Portugal. D. Batista was funded by FCT grant SFRH/BPD/104629/2014

    Antiaterogenicidad in vitro de extractos del alga marina Halimeda incrassata: actividad antioxidante y estudios de migración en células de la musculatura lisa

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    Aim: The aim of this work was to evaluate the in vitro atheroprotective potential of the seaweed Halimeda incrassata in smooth muscle cell migration and lipoprotein oxidation in relation to its antioxidant activity.Material and methods: Antioxidant activity was determinate by DPPH• radical scavenging assay and ORAC method. The inhibitory effect of the aqueous extract on LDL oxidation mediated by Cu2+ ions was determinate by TBARS and conjugated diene quantification. The effect of the seaweed aqueous extract on smooth muscle cell migration was evaluated in MOVAS-1 mouse aortic smooth muscle cell.Results: The inhibitory effect of the aqueous extract on lipoprotein oxidation mediated by Cu2+ was demonstrated. Seaweed extract caused dose-dependent inhibition of TBARS (IC50 = 0.8 mg/mL) and conjugated dienes formation. The seaweed had a high antioxidant activity in the assays performed. The activity could be related to the phenolic content of Halimeda incrassata.Conclusions: In summary, the results of this study represent a further step in the characterization of the atheroprotective action of Halimeda incrassata and indicate the seaweed could be used for a nutraceutical and/or phytoterapeutic application.Objetivos: El objetivo de este trabajo fue evaluar el potencial ateroprotector in vitro del alga Halimeda incrassata en la migración de células de músculo liso de ratón y la oxidación de lipoproteínas en relación con su actividad antioxidante.Material y métodos: La actividad antioxidante fue determinada mediante los métodos de inhibición de radicales DPPH y la Capacidad antioxidante total (ORAC). La actividad inhibitoria de la oxidación de LDL mediada por iones Cu2+ se determinó por la cuantificación de TBARS y dienos conjugados. El efecto del extracto acuoso sobre la migración de las células de músculo liso se evaluó en la línea de células de músculo liso aórtica de ratón MOVAS-1.Resultados: Se demostró el efecto inhibidor del extracto sobre la oxidación de LDL mediada por Cu2+. El extracto del alga causa inhibición dosis-dependiente de la formación de TBARS (IC50 = 0,8 mg/mL) y dienos conjugados. Las algas tuvieron una alta actividad antioxidante en los ensayos realizados y podría estar relacionada con el contenido de compuestos fenólicos.Conclusiones: Los resultados de este trabajo representan un paso más en la caracterización de la acción ateroprotectora de Halimeda incrassata y evidencian sus posibles aplicaciones como nutracéutico y/o fitofármaco

    Genome wide analysis of gene expression changes in skin from patients with type 2 diabetes

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    Non-healing chronic ulcers are a serious complication of diabetes and are a major healthcare problem. While a host of treatments have been explored to heal or prevent these ulcers from forming, these treatments have not been found to be consistently effective in clinical trials. An understanding of the changes in gene expression in the skin of diabetic patients may provide insight into the processes and mechanisms that precede the formation of non-healing ulcers. In this study, we investigated genome wide changes in gene expression in skin between patients with type 2 diabetes and non-diabetic patients using next generation sequencing. We compared the gene expression in skin samples taken from 27 patients (13 with type 2 diabetes and 14 non-diabetic). This information may be useful in identifying the causal factors and potential therapeutic targets for the prevention and treatment of diabetic related diseases

    Sugarcane stem borers of the Colombian Cauca River Valley: current pest status, biology, and control

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    Citation: Vargas, G., Gomez, L. A., & Michaud, J. P. (2015). Sugarcane stem borers of the Colombian Cauca River Valley: current pest status, biology, and control. Florida Entomologist, 98(2), 728-735. Retrieved from ://WOS:000356451400049Sugarcane stem borers of the genus of Diatraea (Lepidoptera: Crambidae) form a species complex that causes serious economic losses to sugarcane production in the Cauca River Valley and other regions of Colombia. Two primary species, Diatraea saccharalis (F.) and D. indigenella Dyar and Heinrich, have been effectively managed for more than 4 decades through augmentative releases of the tachinid flies Lydella minense (Townsend) and Billaea claripalpis (Wulp) (Diptera: Tachinidae) and the egg parasitoid Trichogramma exiguum Pinto & Platner (Hymenoptera: Trichogrammatidae). Here we review the current pest status of Diatraea species, damage assessment protocols, management tactics, and the environmental factors and cultural practices that can affect biological control outcomes. Recent changes in the cultivars grown have the potential to increase pest populations and diminish biological control efficacy. Additionally, recent outbreaks of new Diatraea species may further increase overall pest pressure. Thus, there is a need to develop supplementary tactics for the management of these pests that will be compatible with biological control, as well as more reliable protocols for assessing host plant resistance against the increase in infestation intensity

    Increased risk of venous thrombosis by AB alleles of the ABO blood group and Factor V Leiden in a Brazilian population

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    Most cases of a predisposition to venous thrombosis are caused by resistance to activated protein C, associated in 95% of cases with the Factor V Leiden allele (FVL or R506Q). Several recent studies report a further increased risk of thrombosis by an association between the AB alleles of the ABO blood group and Factor V Leiden. The present study investigated this association with deep vein thrombosis (DVT) in individuals treated at the Hemocentro de Pernambuco in northeastern Brazil. A case-control comparison showed a significant risk of thrombosis in the presence of Factor V Leiden (OR = 10.1), which was approximately doubled when the AB alleles of the ABO blood group were present as well (OR = 22.3). These results confirm that the increased risk of deep vein thrombosis in the combined presence of AB alleles and Factor V Leiden is also applicable to the Brazilian population suggesting that ABO blood group typing should be routinely added to FVL in studies involving thrombosis
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