733 research outputs found
Fiscal Policy Discretion, Private Spending, and Crisis Episodes
In this paper, we assess the impact of fiscal policy discretion on economic activity in the short and medium-term. Using a panel of 132 countries from 1960 to 2008, we find that fiscal policy discretion provides a net stimulus to the economy in the short-run and crowding-in effects are amplified once crisis episodes are controlled for– in particular, banking crises - giving a great scope for fiscal policy stimulus packages. However, crowding-out effects take over in the long-run – especially, in the case of debt crises -, in line with the concerns about long-term debt sustainability.Fiscal policy discretion, GDP growth, private consumption, private investment, crowding-in, crowding-out.
Species of Bursaphelenchus Fuchs, 1937 (Nematoda: Parasitaphelenchidae) and other nematode genera associated with insects from Pinus pinaster in Portugal
Insects associated with maritime pine, Pinus pinaster, in Portugal were collected
and screened for the presence of Bursaphelenchus species. Nematodes were
identified using Internal Transcribed Spacers-Restriction Fragment Length
Polymorphism (ITS-RFLP) analysis of dauer juveniles and morphological
identification of adults that developed from dauer juveniles on fungal cultures
or on cultures in pine wood segments at 26 C. Several associations are
described: Bursaphelenchus teratospicularis and Bursaphelenchus sexdentati are
associated with Orthotomicus erosus; Bursaphelenchus tusciae, B. sexdentati and/or
Bursaphelenchus pinophilus with Hylurgus ligniperda and Bursaphelenchus hellenicus
with Tomicus piniperda, Ips sexdentatus and H. ligniperda. An unidentified
Bursaphelenchus species is vectored by Hylobius sp. The previously reported
association of Bursaphelenchus xylophilus with Monochamus galloprovincialis
was confirmed. The association of Bursaphelenchus leoni with Pityogenes sp. is
not definitively established and needs further studies for clarification.
Other nematode genera besides Bursaphelenchus were found to be associated
with the insects sampled, including two different species of Ektaphelenchus, Parasitorhabditis
sp., Parasitaphelenchus sp., Contortylenchus sp. and other unidentified
nematodes. The Ektaphelenchus species found in O. erosus is morphologically
similar to B. teratospicularis found in the same insect; adults of both the species
are found in cocoon-like structures under the elytra of the insects.
Introduction
Approximately one third of the nematodes belonging to
the order Aphelenchida Siddiqi, 1980 are associated with
insects (Poinar, 1983). These nematodes establish a variety
of associations with the insects, which may be
described as commensalism, e.g. phoresy (to the benefit
of the nematode but not affecting the insect), mutualism
(both the organisms benefit) or parasitism (nematodes
benefit at the expense of the insect) (Giblin-Davis,
2004).
Most Bursaphelenchus Fuchs, 1937 species are mycetophagous,
feeding on fungi in the galleries of bark beetles
and thu
Demonstration of fundamental mode only propagation in highly multimode fibre for high power EDFAs
The use of short lengths of large core phosphate glass fibre, doped with high
concentrations of Er or Er:Yb represents an attractive route to achieving high
power erbium doped fibre amplifiers (EDFAs) and lasers (EDFLs). With the aim of
investigating the potential of achieving diffraction limited output from such
large core fibres, we present experimental results of fundamental mode
propagation through a 20 cm length of passive 300 micrometer core multimode
fibre when the input is a well-aligned Gaussian beam. Through careful control
of fibre geometry, input beam parameters and alignment, we measured an output M
squared of 1.1 + - 0.05. The fibre had a numerical aperture of 0.389, implying
a V number of 236.8. To our knowledge, this is the largest core fibre through
which diffraction limited fundamental mode propagation has been demonstrated.
Although the results presented here relate to undoped fibre, they do provide
the practical basis for a new generation of EDFAs and EDFLs.Comment: 5 figure
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
Tronchuda cabbage flavonoids uptake by Pieris brassicae
The flavonoid pattern of larvae of cabbage white butterfly (Pieris brassicae L.; Lepidoptera: Pieridae) reared on the leaves of tronchuda
cabbage was analysed by HPLC-DAD-MS/MS-ESI. Twenty flavonoids were identified or characterised, namely 16 kaempferol
and four quercetin derivatives. Kaempferol 3-O-sophoroside, a minor component of tronchuda cabbage, was found to be the main component
in P. brassicae (15.8%). Apart from this, only two other flavonoids present in significant amounts in tronchuda cabbage (kaempferol
3-O-sophoroside-7-O-glucoside and kaempferol 3-O-sophoroside-7-O-sophoroside) were found in the larvae. The larvae have high
amounts of quercetin derivatives (18.5%), which were present only in trace amounts in tronchuda cabbage extracts, suggesting that
P. brassicae is able to selectively sequester these flavonoids. The occurrence of a high content of flavonoids not detectable in tronchuda
cabbage extracts indicates that P. brassicae larvae are able to metabolize dietary flavonoids
Chemical composition and antioxidant activity of tronchuda cabbage internal leaves
A phytochemical study was undertaken on the
internal leaves of tronchuda cabbage (Brassica oleracea L. var. costata DC). Seventeen phenolic compounds were
characterized and quantified by reversed-phase HPLCDAD-ESI-MSn and HPLC/DAD, respectively: quercetin 3-O-sophoroside-7-O-glucoside, 3-p-coumaroylquinic acid,
kaempferol 3-O-sophoroside-7-O-glucoside, kaempferol
3-O-(caffeoyl)-sophoroside-7-O-glucoside, sinapoyl glucoside
acid, kaempferol 3-O-(sinapoyl)-sophoroside-7-Oglucoside,
kaempferol 3-O-(feruloyl)-sophoroside-7-Oglucoside,
kaempferol 3-O-(p-coumaroyl)-sophoroside-
7-O-glucoside, 4-p-coumaroylquinic acid, sinapic acid,
kaempferol 3-O-sophoroside, 3 isomeric forms of 1,2-
disinapoylgentiobiose, 1-sinapoyl-2-feruloylgentiobiose,
1,2,2-trisinapoylgentiobiose and 1,2'-disinapoyl-2-feruloylgentiobiose.
Seven organic acids (aconitic, citric,
ascorbic, malic, quinic, shikimic and fumaric acids) were
also identified and quantified. The hot water extract of
tronchuda cabbage internal leaves was investigated for its capacity to act as a scavenger of DPPH- radical and reactive
oxygen species (superoxide radical, hydroxyl radical
and hypochlorous acid), exhibiting antioxidant capacity in
a concentration dependent manner against all radicals.Tronchuda cabbage internal leave
Antioxidative properties of tronchuda cabbage (Brassica oleracea L. var. costata DC) external leaves against DPPH, superoxide radical, hydroxyl radical and hypochlorous acid
The ability of the aqueous extract of tronchuda cabbage (Brassica oleracea L. var. costata DC) external leaves to act as a
scavenger of DPPH- and reactive oxygen species (superoxide radical, hydroxyl radical and hypochlorous acid) was investigated.
A phytochemical study was also undertaken, and thirteen phenolic compounds and five organic acids were identified and quantified.
Tronchuda cabbage extracts exhibited antioxidant capacity in a concentration-dependent manner in all assays, although some
pro-oxidant effect was also noticed. The samples with higher phenolic and organic acid contents displayed the major antioxidant
potentials
Immunoproteomic analysis of Plasmodium falciparum antigens using sera from patients with clinical history of imported malaria.
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