1,545 research outputs found
Ontogenetic stage-specific reciprocal intraguild predation
The size or stage of interacting individuals is known to affect the outcome of ecological interactions and can have important consequences for population dynamics. This is also true for intraguild predation (the killing and eating of potential competitors), where the size or ontogenetic stage of an individual determines whether it is the intraguild predator or the intraguild prey. Studying size- or stage-specific interactions is therefore important, but can be challenging in species with complex life histories. Here, we investigated predatory interactions of all feeding stages of the two predatory mite species Neoseiulus californicus and Phytoseiulus macropilis, both of which have complex life cycles, typical for predatory arthropods. Populations of these two species compete for two-spotted spider mites, their prey. We evaluated both the capacity to kill stages of the other predator species and the capacity to benefit from feeding on these stages, both prerequisites for the occurrence of intraguild predation. Ontogeny played a critical role in the occurrence of intraguild predation. Whereas the juveniles of P. macropilis developed from larva until adulthood when feeding on N. californicus eggs, interestingly, adult female P. macropilis did not feed on the smaller stages of the other species. We furthermore show that intraguild predation was reciprocal: both juveniles and adult females of N. californicus preyed on the smallest stages of P. macropilis. These results suggest that a proper analysis of the interactions between pairs of species involved in intraguild predation should start with an inventory of the interactions among all ontogenetic stages of these species
Test of Universality in Anisotropic 3D Ising Model
Chen and Dohm predicted theoretically in 2004 that the widely believed
universality principle is violated in the Ising model on the simple cubic
lattice with more than only six nearest neighbours. Schulte and Drope by Monte
Carlo simulations found such violation, but not in the predicted direction.
Selke and Shchur tested the square lattice. Here we check only this
universality for the susceptibility ratio near the critical point. For this
purpose we study first the standard Ising model on a simple cubic lattice with
six nearest neighbours, then with six nearest and twelve next-nearest
neighbours, and compare the results with the Chen-Dohm lattice of six nearest
neighbours and only half of the twelve next-nearest neighbours. We do not
confirm the violation of universality found by Schulte and Drope in the
susceptibility ratio.Comment: 6 pages including 4 figures, Physica A, in pres
Análise e reflexão em torno das obrigações de relato e respetivo grau de cumprimento das entidades do setor financeiro em São Tomé e Príncipe
O presente trabalho tem como objetivo discutir, com recurso a uma metodologia qualitativa e descritiva, as obrigações de relato das entidades do setor financeiro em São Tomé e Príncipe (STP), respetivo grau de cumprimento, quem as supervisiona e como o fazem. A recolha de informação foi feita a partir da análise aos relatórios e contas anuais (período de 2012 a 2014) dos sete bancos comerciais que operam no país, a totalidade da população, e com recurso a entrevistas semiestruturadas, efetuadas no mês de janeiro de 2016 a um profissional habilitado de cada uma dessas instituições. Os resultados mostram que a maioria não cumpre com todas as obrigações de relato, pelo que o grau de cumprimento fica aquém do expectável e, inclusive, do legalmente imposto. A supervisão é exercida, exclusivamente, pelo Banco Central de STP e apresenta um pendor eminentemente pedagógico com o objetivo de sensibilizar e melhorar o panorama atual.info:eu-repo/semantics/publishedVersio
Detecting respiratory bacterial communities of wild dolphins: Implications for animal health
Infectious diseases contribute to the vulnerable status of marine mammals, including respiratory illnesses. This study aimed to capture exhaled breath condensate (blow) for microbial identification from wild Indo-Pacific bottlenose dolphins Tursiops aduncus. Individual dolphins were sampled by holding a funnel connected to a 50 ml centrifuge tube over the blowhole of the animal near shore in Shark Bay (SB), Western Australia. Four individuals were sampled on 2 occasions along with seawater samples. Comparative blow and pool water samples were collected from 4 individual common bottlenose dolphins Tursiops truncatus housed in the National Aquarium (NA), Baltimore, Maryland, USA. Bacteria were identified using the V4 region of the 16S rRNA gene from extracted DNA. We identified bacteria independent of seawater in SB dolphins, which included the classes Alphaproteobacteria (26.1%) and Gammaproteobacteria (25.8%); the phyla Bacteroidetes (15.6%) and Fusobacteria (7.2%); and the genera Pseudomonas (11.5%), Pedomicrobium (4.5%), Streptobacillus (3.7%), Phenylobacterium (2.2%) and Sphingomonas (2.1%). There were broad similarities in phyla between SB and NA dolphins yet there were differences between lower taxonomic groups. A number of operational taxonomic units (OTUs) were shared between dolphin individuals, which may be a result of their genetic lineage (siblings or parentage), shared living and social interactions. A number of genera were observed in SB dolphins which have species known to be infectious in marine mammals such as Pseudomonas, Mycoplasma and Streptococcus. This study successfully characterised bacteria from DNA captured in blow from wild dolphins. The ability to capture these communities from individuals in the wild provides a novel health indicator
E 1 Gap Of Wurtzite Inas Single Nanowires Measured By Means Of Resonant Raman Spectroscopy
Indium arsenide nanowires were synthesized with an intermixing of wurtzite and zincblende structure by chemical beam epitaxy with the vapor-liquid-solid mechanism. Resonant Raman spectroscopy of the transverse optical phonon mode at 215cm -1 reveals an E 1 gap of 2.47 eV which is assigned to the electronic band gap at the A point in the indium arsenide wurtzite phase. © 2011 American Institute of Physics.1399473474 Int. Union Pure Appl. Phys. (IUPAP C8 Comm.),Korean Ministry of Education, Science and Technology,Seoul Metropolitan Government,Office of Naval Research Global,Korea Tourism OrganizationDick, K.A., (2008) Prog. Cryst. Growth Charact. Mater., 54, pp. 138-173Milnes, A.G., Polyakov, A.Y., (1993) Mater. Sci. Eng. B, 18, pp. 237-259Dayeh, S.A., Susac, D., Kavanagh, K.L., Yu, E.T., Wang, D., (2009) Adv. Mater., 19, pp. 2102-2108Cardona, M., (1961) J. Appl. Phys., 32 (SUPPL.), pp. 2151-2155Antoci, S., Reguzzoni, E., Samoggia, G., (1970) Phys. Rev. Lett., 24, pp. 1304-1307Arguello, C.A., Rousseau, D.L., Porto, S.P.S., (1969) Phys. Rev., 181, pp. 1351-136
2-Styrylchromones: novel strong scavengers of reactive oxygen and nitrogen species
http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=1&SID=S2NjaL1GBbk143plPl1&page=1&doc=1&colname=WOS2-Styrylchromones are a small group of naturally occurring chromones, vinylogues of flavones (2-phenylchromones).
Natural and synthetic 2-styrylchromones have been tested in different biological systems, showing activities with potential therapeutic
applications. In particular, the potential and hitherto understudied antioxidant behavior of these compounds has been raised as a
matter of interest. Thus the present work consisted in the study of the in vitro scavenging activities for reactive oxygen species (ROS)
and reactive nitrogen species (RNS) of various 2-styrylchromone derivatives and structurally similar flavonoids. Some of the studied
2-styrylchromones proved to be extremely efficient scavengers of the different ROS and RNS, showing, in some cases, IC50s under
1 lM. The hydroxylation pattern of 2-styrylchromones, especially in the B-ring but also in the A ring, modulates the activity of these
compounds, the catecholic derivatives being the most effective scavengers. The styryl pattern also contributes to their observed outstanding
antioxidant activity. In conclusion, the scavenging activities for ROS/RNS of 2-styrylchromone derivatives, here shown for
the first time, provide novel and most promising compounds to be applied as antioxidants
Anti-inflammatory potential of 2-styrylchromones regarding their interference with arachidonic acid metabolic pathways
Cyclooxygenases (COXs) are the key enzymes in the biosynthesis of prostanoids. COX-1 is a constitutive
enzyme while the expression of COX-2 is highly stimulated in the event of inflammatory processes,
leading to the production of large amounts of prostaglandins (PGs), in particular PGE2 and PGI2, which
are pro-inflammatory mediators.
Lipoxygenases (LOXs) are enzymes that produce hydroxy acids and leukotrienes (LTs). 5-LOX
metabolizes arachidonic acid to yield, among other products, LTB4, a potent chemoattractantmediator of
inflammation.
The aim of the present work was to evaluate the anti-inflammatory potential of 2-styrylchromones
(2-SC), a chemical family of oxygen heterocyclic compounds, vinylogues of flavones (2-phenylchromones),
by studying their COX-1 and COX-2 inhibitory capacity as well as their effects on the LTB4
production by stimulated human polymorphonuclear leukocytes (PMNL).
Some of the tested 2-SC were able to inhibit both COX-1 activity and LTB4 production which makes
them dual inhibitors of the COX and 5-LOX pathways. The most effective compounds in this study were
those having structural moieties with proved antioxidant activity (30,40-catechol and 40-phenol
substituted B-rings).
This type of compounds may exhibit anti-inflammatory activity with a wider spectrum than that of
classical non-steroidal anti-inflammatory drugs (NSAIDs) by inhibiting 5-LOX product-mediated
inflammatory reactions, towards which NSAIDs are ineffective.The authors acknowledge FCT and FEDER financial support for
the project POCI/QUI/59284/2004 and the Organic Chemistry
Research Unit (no. 62; Univ. Aveiro). Ana Gomes acknowledges FCT
and FSE her PhD grant (SFRH/BD/23299/2005)
Cyclic voltammetric analysis of 2-styrylchromones: Relationship with the antioxidant activity
2-Styrylchromones (2-SC) are a chemical family of oxygen heterocyclic compounds, vinylogues of flavones
(2-phenylchromones), whose occurrence in nature has been reported. Recently, several 2-SC derivatives
were demonstrated to have antioxidant properties, namely, xanthine oxidase inhibition,
hepatoprotection against pro-oxidant agents in cellular and non-cellular systems and scavenging activity
against reactive oxygen and reactive nitrogen species (ROS and RNS). Considering these antioxidant properties,
it may be hypothesised that the electrochemical redox behaviour of 2-SC contributes significantly
to their activity. To test this hypothesis, the electrochemical behaviour of different 2-SC was studied,
together with a number of flavonoids with well-known antioxidant activities, by cyclic voltammetry,
and the results correlated to their ability to scavenge ROS and RNS.
The results obtained showed that 2-SC with a catecholic B-ring have a low oxidation peak potential corresponding
to the oxidation of the 30,40-OH (catechol) moiety. The compounds with a phenolic B-ring
have a common peak, with oxidation potential values of about +0.4/+0.5 V versus Ag/AgCl, corresponding
to the oxidation of the 40-OH. The oxidation of the hydroxyl substituents in the A-ring generated peaks of
higher potentials (+0.7/+0.8 V vs Ag/AgCl). The results from the scavenging assays were in agreement
with those obtained from the cyclic voltammetry, that is, higher scavenging effects corresponded to
lower values of oxidation potentials, with significant correlation coefficients. The values obtained for
the studied flavonoids are in accordance with the literature, and reflect their relative antioxidant activity,
when compared to the studied 2-SC. Thus, in this family of compounds, oxidation potentials obtained by
cyclic voltammetry seem to be applicable as a general indicator of radical scavenging activity.The authors acknowledge FCT and FEDER financial support for
the Project POCI/QUI/59284/2004. Ana Gomes acknowledges FCT
and FSE her Ph.D. Grant (SFRH/BD/23299/2005)
Quality Of Soy Bean Seeds Under Tillage With Differe Nt Amounts Of Waste Of Black Oats, Common Vetch And For Age Turnip
Adjusting the cover crop to the agricultural system is essential to reach success during a crop introduction, since this management can influence development, productivity and produced seeds quality. For the soybean cultivar CD 202, traditional, half, and double amounts of crop waste produced by black oats, and a consortium of black oat, common vetch and forage turnip, were evaluated. Tests comprised emergence (emergency speed index (ESI) and emergence rate (ER)), development, field productivity and quality of seeds (germination percentage, accelerated aging, purity, 100-seed weight, and water content). The experimental design was of split plots and the mean values were compared through the Scott-Knott test at a 5% significance level, totaling seven treatments with five replications each. No differences were found in germination percentage, water content, and final height of plants. Some treatments differed in germination and waste use increased ESI; ER was superior for black oats and the best productivity was found under double amount of straw, on both cover crops. The seed strength decreased the under consortium, as shown by accelerated aging under the consortium. The purity of seeds was lower for black oats, decreasing with the least amount of crop waste. The 100-seed weight was lower with the double amount in oats; however, under the consortium the use of cover crop increased their weight. Thus, these species can be a good alternatives for soybean rotation on winter.384292297Bortolini, M.F., Fortes, M.T., Efeitos alelopáticos sobre a germinação de sementes de soja (Glycine max L. Merrill) (2005) Semina: Ciênc. Agr., 26, pp. 5-10(2009) Indicadores da Agropecuária. Ano XVIII, No 1. Compan Hia Nacional de Abastecimento, 64p. , CONAB, Brasília, Brazil(2009) Soja CD 202. Cooperativa Central de Pesquisa Agrícola, , www.coodetec.com.br/php/detalhes_cultivar.php?id=20, CIDADE?, Brazil, (Cons. 02/25/2009)Correia, N.M., Centurion, M.A.P.C., Alves, P.L.C.A., Inf luência de extratos aquosos de sorgo sobre a germinação e o desenvolvimento de plântulas de soja (2005) Ciênc. Rural, 35, pp. 498-503Edmond, J.B., Drapalla, W.J., The effects of temperature, sana and soil, and acetone on ger mination oj ok ra seed (1958) Proc. Am. Soc. Hort. Sci., 71, pp. 428-443(2000) A Cultura da Soja No Brasil, , EMBRAPA SOJA, Londrina, Brazil. CD-ROM(2005) Tecnologia da Produção da Soja. Empresa de Pesquisa Agropecuária, 208p. , EMBRAPA SOJA, Londrina, Brazil(2008) Tecnologia de Produção de Soja. Região Central Do Brasil, 280p. , EMBRAPA SOJA, Empresa de Pesquisa Agropecuária. Embrapa Cerrados: Embrapa Agropecuária Oeste. Londrina, BrazilFerreira, D.F., (1999) Sisvar: Sistema de Análise de Variância Para Dados Balanceados, , DEX / UFLA: Lavras, Brazil(2009) Prognóstico da Produção Agrícola Nacional, , www.ibge.gov.br/home/estatistica/indicadores/agropecuaria/lspa/ lspa_200812-11.shtm, Instituto Brasileiro de Geografia e Estatística, (Cons. 01/16/2009)Kubo, C.T., Produtividade de soja em plantio direto em sucessão ao trigo, aveia branca, aveia preta com e sem adubação nit rogenada (2007) Acta Sci. Agron., 29, pp. 235-240Lopes, R.A.P., Pin Heiro Neto, R., Braccini, A.L., Souza, E.G., Efeito de diferentes coberturas vegetais e sistemas de preparo do solo na produção da cultura da soja (2007) Acta Sci. Agron., 29, pp. 507-515Maguire, J.D., Seeds of germination- aid selection and evaluation seedling emergence and vigor (1962) Crop Sci., 2, pp. 176-177Marcos Filho, J., Teste de envelhecimento acelerado. Cap. 3. (1999) Seed Vigor: Concepts and Tests, pp. 1-24. , Krzyzanowski EFC, Vieira RD, Neto JBF (Eds.), Associação Brasileira de Tecnologia de Sementes. Londrina, Brazil. 218 ppMarcos Filho, J., Cicero, S.M., Silva, W.R., (1987) Avaliação da Qualidade de Sementes, 230p. , FEALQ. Piracicaba, BrazilMartins, G.I., (2006) Potencial Alelopático de Plantas de Cobertura Na Germinação de Sementes e Crescimento de Plântulas de Soja. Trabalho de Conclusão de Curso, 42p. , Universidade Estadual do Oeste do Paraná. Brazil(2009) Regras Para Análise de Sementes. 388 Mapa/ACS, 399p. , MAPA, Ministério da Agricultura, Pecuária e Abastecimento. Brasília, BrazilNedel, J.L., Fundamentos da qualidade de sementes (2003) Sementes: Fundamentos Científicos e Tecnológicos, pp. 95-138. , Peske ST, Rosenthal MD, Rota GR (Eds.), Universidade Federal de Pelotas. BrazilNóbrega, L.H.P., Germinação de sementes e crescimento de plântulas de soja (Glycine max L. Merrill) sob cobertura vegetal (2009) Acta Sci. Agron., 31, pp. 461-465Nunes, U.R., Qualidade fisiológica de sementes de feijão em plantio direto sobre diferentes coberturas de plantas em Diamantina MG (2007) Ciênc. Agrotécn., 31, pp. 1737-1743Piccolo, G., (2008) Manejo de Coberturas Vegetais Na Cultura da Soja, 63p. , Thesis. Universidade Estadual do Oeste do Paraná, Unioeste. BrazilRice, E.L., (1974) Allelopathy, 333p. , Academic Press. New York, USA(2008) Área e Produção: Principais Culturas Do Paraná, , www.seab.pr.gov.br/, SEAB, Secretaria da Agricultura e do Abastecimento do Paraná. (Cons. 12/22/2008)Souza, C.M., Pires, F.R., (2002) Adubação Verde e Rotação de Culturas, 72p. , Universidade Federal de Viçosa. BrasilSouza Filho, A.P., Alves, S.M., Mecanismos de ação dos agentes alelopáticos (2002) Alelopatia. Princípios Básicos e Aspectos Gerais. Embrapa Amazônia Oriental, pp. 132-154. , Souza Filho AP, Alves SM (Eds.), Belém, BrasilTokura, L.K., Nóbrega, L.H.P., Alelopatia de cultivos de cobertura vegetal sobre plantas infestantes (2006) Acta Sci. Agron., 28, pp. 379-38
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