7,441 research outputs found
Regions and Low-Wage Mobility in Portugal
This paper examines the impact of regions on low wage incidence and mobility in Portugal. In particular, we intend to examine to what extent there are significant differences between the region of Lisbon and the rest of the country. The results indicate that, everything else the same, the region is an important determinant of the probability of the individual being found into the low wage class (defined as two-thirds of the median hourly wage), even in a small country like Portugal. It is also affects the probability of leaving low-pay. In particular, equally-skilled workers working in the region of Lisbon are less-likely to be low-paid than the other workers. They are also more likely to escape from the low-pay segment. Other variables of great importance on low pay determination and mobility, and in both regions, are the level of education of the workers, gender and the size of the firm.
Pay as You Go: A Generic Crypto Tolling Architecture
The imminent pervasive adoption of vehicular communication, based on
dedicated short-range technology (ETSI ITS G5 or IEEE WAVE), 5G, or both, will
foster a richer service ecosystem for vehicular applications. The appearance of
new cryptography based solutions envisaging digital identity and currency
exchange are set to stem new approaches for existing and future challenges.
This paper presents a novel tolling architecture that harnesses the
availability of 5G C-V2X connectivity for open road tolling using smartphones,
IOTA as the digital currency and Hyperledger Indy for identity validation. An
experimental feasibility analysis is used to validate the proposed architecture
for secure, private and convenient electronic toll payment
The History of Expansion of the Genus Bursaphelenchus (Nematoda: Aphelenchida: Parasitaphelenchidae)
Because of globalization and removal of geographical
barriers, frequent biological invasions of introduced
species become an urgent environmental problem.
According to the Convention on Biological Diversity
(CBD), precise identification of dangerous aggressive
species at the early stages of their invasion to new
regions is the most important component of the environmental
control and monitoring. To resist the potential
environmental hazard, the precise data are required
on the current distribution and history of expansion of
pests that are of global economic importance
A taxonomic database for the pinewood nematode Bursaphelenchus xylophilus, and other Bursaphelenchus species
The main objective of this project is to develop an information
database with the inclusion of text (research articles, keys, bibliography,
etc.), images (jpeg files), video clips (mpeg files), in order to collect in one
physical format (CD-ROM) all relevant information related to the taxonomy
of pine wood nematode (PWN), Bursaphelenchus xylophilus, as well as other
Bursaphelenchus species. Initially, all major research papers will be scanned
in ‘pdf’ format. All available images of quality and importance to the subject
will also be scanned from either journals, bulletins, reports, or obtained
privately from colleagues’ image collections. In certain cases, image quality
(brightness, contrast, colour) may be enhanced with Adobe Photoshop. Short
video clips will be compressed to ‘mpeg’ format for inclusion in the CD-ROM.
An updated and broad bibliography will be included, as well as an intuitive
taxonomic key, based on classical dicotomous keys but with a better and more
intuitive presentation. Pre-existing images will be used in most cases; however,
nematode specimens may need to be observed and photographed (jpeg image)
in the lab. All the incorporated elements will be interlinked for ease of search
from text to image to video. The total collection of images may be viewed
individually using ‘Extensis Portfolio’. The final product will be PC and Mac
compatible. Future editions/updates will be developed. Ultimately, researchers,
technicians and political decision-makers will have at their disposal a practical
and readily available source of information on this extremely important pest and
pathogen. Colleagues working with PWN are encouraged to provide materials
for this task
Robustness of the O() universality class
We calculate the critical exponents for Lorentz-violating O()
scalar field theories by using two independent methods. In
the first situation we renormalize a massless theory by utilizing normalization
conditions. An identical task is fulfilled in the second case in a massive
version of the same theory, previously renormalized in the BPHZ method in four
dimensions. We show that although the renormalization constants, the
and anomalous dimensions acquire Lorentz-violating quantum corrections, the
outcome for the critical exponents in both methods are identical and
furthermore they are equal to their Lorentz-invariant counterparts. Finally we
generalize the last two results for all loop levels and we provide symmetry
arguments for justifying the latter
Contagion effects of the US Subprime Crisis on Developed Countries
This study assesses whether capital markets of developed countries reflect the effects of financial contagion from the US subprime crisis and, in such case, if the intensity of contagion differs across countries. Adopting a definition of contagion that relates the phenomenon to an increase of cross-market linkages following a shock, copula models are used to analyse how the connections between the US and each market in the sample, evolved from the pre-crisis to the crisis period. The results suggest that markets in Canada, Japan, Italy, France and the United Kingdom display significant levels of contagion, which are less relevant in Germany. Canada appears to be the country where the highest intensity of contagion is observed.G7, subprime crisis, contagion, copula, event study.
A synopsis of the genus Bursaphelenchus Fuchs, 1937 (Aphelenchida: Parasitaphelenchidae) with keys to species
The 75 valid species of the genus Bursaphelenchus are listed together with their synonyms. Diagnostic characters and
their states are discussed and illustrated. Tabular and traditional text keys are provided for the genus. Two new subspecies are proposed
to distinguish populations of B. piniperdae and B. poligraphi, as described by Rühm (1956), from the original descriptions of these
species published by Fuchs (1937). Known records of Bursaphelenchus species with their associated natural vectors, plants and plant
families are given. Dendrograms of species relationships (UPGMA, standard distance: mean character difference) based on combined
taxonomic characters and also on spicule characters only, are provided. Discussion as to whether the species groups are natural or
artificial (and therefore purely diagnostic) is based on their relationships in the dendrogram and the vector and associated plant ranges
of the species. Of the six species groups distinguished, two appear to represent natural assemblages, these being the xylophilus-group
(with ten species) and the hunti-group (seven species), of which two, B. cocophilus and B. dongguanensis, form the cocophilus-cluster
which is separated on the dendrogram from the main clusters. The remaining four species groups appear to be artificial and purely
diagnostic in function, namely the aberrans-group (four species); the eidmanni-group (six species); the borealis-group (five species),
and the piniperdae-group (43 species). Two new subspecies, both in the piniperdae-group, viz. B. piniperdae ruehmpiniperdae n. subsp.
and B. poligraphi ruehmpoligraphi n. subsp., are proposed and diagnosed from B. piniperdae piniperdae and B. poligraphi poligraphi
the respective type subspecies. Bursaphelenchus dongguanensis is regarded as being a valid member of the genus and its transfer to
Parasitaphelenchus is rejected
Computerized key of the genus genus Laimaphelenchus Fuchs, 1937
The Order Aphelenchida contains several genera of economic importance, namely Aphelenchoides and Bursaphelenchus. Nematode species belonging to these 2 genera frequently co-habit with other genera such as Laimaphelenchus. It is therefore important to clearly distinguish them, as well as understand the group´s biodiversity. A computerized, or e-key, for the genus Laimaphelenchus Fuchs has been developed in the BiKey Identification system (Dianov & Lobanov, 1996-2004). The e-key includes 14 species and 34 characters (from 2 to 6 character states each). It also includes the built-in algorithm ranging characters according their diagnostic values to minimize the number of the diagnosis steps (average number of steps is 2.7; values are re-calculated at each step). The most important characters (as calculated by BiKey) are: length of posterior branch of the female genital system; excretory pore position; vulval anterior flap shape; number pairs of mail tale papillae; male bursa shape (ventral view); number of tail tip setae in female; female tail tip stub shape; presence of mucro on tail tip in male. Key is pictorial (image-operating), multientry, as other BiKey products
Review of the genus Bursaphelenchus Fuchs, 1937 (Nematoda, Aphelenchida) with some conclusions on the host-parasite and vector-parasite evolution.
INTRODUCTION AND GOALS: Genus Bursaphelenchus includes several pests of the world importance for the rural economy, the most dangerous are the Bursaphelenchus xylophilus (the pinewood nematode caused decline of the pine trees in south Asia and in one spot area in Europe, Portugal, Peninsula de Setubal) and the Bursaphelenchus cocophilus, causing the decline of coco-palm plantations in Carribean and Latin American regions. The peculiarity of the host-parasite association of the genus that the nematode life cycle includes three trophic components: plant (mostly a tree), insect vector and a fungus. Goals of the presentation is to list all species of the world fauna and all efficient diagnostic characters, then create the identification tool and analyze the similarity of species and possible ways and causes of the host-parasite evolution of the group.
RESULTS: Complete list of species with synonymy and a catalogue of all efficient diagnostic characters with their states, selected from papers of the most experienced taxonomists of the genus, are given for the genus Bursaphelenchus. List of known records of Bursaphelenchus species with names of natural vectors and plants and their families is given (for world pests the most important groups of trees and insects are listed). The tabular, traditional and computer-aided keys are presented. Dendrograms of species relationships (UPGMA, standard distance: mean character difference) based on all efficient taxonomic characters and separately on the spicule characters only, are given. Discussion whether the species groups are natural or purely diagnostic ones is based on the relationships dendrograms and the vector and associated plant ranges of Bursaphelenchus species; the xylophilus species group (B. xylophilus, B. abruptus, B. baujardi, B. conicaudatus, B. eroshenkii, B. fraudulentus, B. kolymensis, B. luxuriosae; B. mucronatus), the hunti group (B. hunti, B. seani, B. kevini and B. fungivorus) are probably the natural ones.
CONCLUSIONS: The parasitic nematode association includes three trophic components: plant, insect vector and fungus. The initial insect-plant complex Scolytidae-Pinaceae is changeable and only in rare occasions the change of the preferred vector to Cerambycidae (the xylophilus group), Hymenoptera (the hunti group) led to formation of the natural species-groups. From the analysis it is clear that although the vector range is changeable it is comparatively more important for the evolution of the genus Bursaphelenchus than associations with plants at the family level. Data on the fungi species (3rd component in natural Bursaphelenchus associations) are insufficient for the detailed comparative analysis
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