4,696 research outputs found
Anisakis infection in allis shad, Alosa alosa (Linnaeus, 1758), and twaite shad, Alosa fallax (Lacépède, 1803), from Western Iberian Peninsula Rivers : zoonotic and ecological implications
Acknowledgments The authors would like to thank M. N. Cueto and J.M. Antonio (ECOBIOMAR) for their excellent technical support and also Rodrigo López for making the map of the study area. We also thank the personal of the Vigo IEO, for providing information about shad captures at sea collected on the basis of national program (AMDES) included in the European Data Collection Framework (DCF) project. We are also grateful to Comandancia Naval de Tui for providing fishing data. M. Bao is supported by a PhD grant from the University of Aberdeen and also by financial support of the contract from the EU Project PARASITE (grant number 312068). This study was partially supported by a PhD grant from the Portuguese Foundation for Science and Technology (FCT) SFRH/BD/44892/2008) and partially supported by the European Regional Development Fund (ERDF) through the COMPETE—Operational Competitiveness Programme and national funds through Foundation for Science and Technology (FCT), under the project BPEst-C/MAR/ LA0015/2013. The authors thank the staff of the Station of Hydrobiology of the USC BEncoro do Con^ due their participation in the surveys. This work has been partially supported by the project 10PXIB2111059PR of the Xunta de Galicia and the project MIGRANET of the Interreg IV BSUDOE (South-West Europe) Territorial Cooperation Programme (SOE2/P2/E288). D.J. Nachón is supported by a PhD grant from the Xunta de Galicia (PRE/2011/198)Peer reviewedPostprin
Identificação de demandas para a cultura do coqueiro.
bitstream/item/90505/1/CPATC-PESQ.-AND.-35-98.pd
Organização do trabalho familiar do espaço rural paraense: novos arranjos na organização do trabalho e na gestão das unidades de produção.
O objetivo do artigo é apresentar uma interpretação acerca da organização do trabalho dos membros das famílias em unidades de produção na comunidade Nossa Senhora de Lourdes identificando novas estratégias de produção e reprodução familiar frente ao contexto de limitações de recursos naturais. As reflexões aqui apresentadas são resultantes de uma pesquisa realizada com famílias agricultoras da comunidade Nossa Senhora de Lourdes localizada no Assentamento Itabocal, município de Mãe do Rio, nordeste paraense. Trata-se de um estudo de caso, realizado a partir de abordagens quantitativas e qualitativas cujas principais categorias de análises são a família, trabalho e seus meios de produção. Os principais resultados mostram que o padrão de exploração do meio natural estabelecido através da agricultura de corte e queima ao longo dos anos nas áreas que compõem a comunidade têm ocasionado problemas associados ao esgotamento de recursos naturais nas unidades de produção familiares e com isso influenciado nos arranjos que se instituem no âmbito do trabalho
On virialization with dark energy
We review the inclusion of dark energy into the formalism of spherical
collapse, and the virialization of a two-component system, made of matter and
dark energy. We compare two approaches in previous studies. The first assumes
that only the matter component virializes, e.g. as in the case of a classic
cosmological constant. The second approach allows the full system to virialize
as a whole. We show that the two approaches give fundamentally different
results for the final state of the system. This might be a signature
discriminating between the classic cosmological constant which cannot virialize
and a dynamical dark energy mimicking a cosmological constant. This signature
is independent of the measured value of the equation of state. An additional
issue which we address is energy non-conservation of the system, which
originates from the homogeneity assumption for the dark energy. We propose a
way to take this energy loss into account.Comment: 15 pages, 5 figures. Accepted for publication in JCA
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Category-based Inductive Learning in Shared NeMuS
One of the main objectives of cognitive science is to use abstraction to create models that represent accurately the cognitive processes that constitute learning, such as categorisation. Relational knowledge is important in this task, since it is through the reasoning processes of induction and analogy that the mind creates categories (it later estabilishes causal relations between them by using induction and abduction), and analogies exemplify crucial properties of relational processing, like structure-consistent mapping[2]. Given the complexity of the task, no model today has accomplished it com- pletely. The associacionist/connectionist approach represents those processes through associations between different informations. That is done by using artifi- cial neural networks. However, it faces a great obstacle: the idea (called proposi- tional fixation) that neural networks could not represent relational knowledge. A recent attempt to tackle the symbolic extraction from artificial neural networks was proposed in [1] The cognitive agent Amao uses a shared Neural Multi-Space (Shared NeMuS) of coded first-order expressions to model the various aspects of logical formulae as separate spaces, with importance vectors of different sizes. Amao [4] uses inverse unification as the generalization mechanism for learning from a set of logically connected expressions of the Herbrand Base (HB). Here We present an experiment to use such learning mechanism to model a simple version of train set from Michalski’s train problem[3
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Learning about Actions and Events in Shared NeMuS
The categorization process of information from pure data or learned in unsuper- vised artificial neural networks is still manual, especially in the labeling phase. Such a process is fundamental to knowledge representation [6], especially for symbol-based systems like logic, natural language processing and textual infor- mation retrieval. Unfortunately, applying categorization theory in large volumes of data does not lead to good results mainly because there is no generic and systematic way of categorizing such data processed by artificial neural networks and joining investigated conceptual structures. Connectionist approaches are capable of extracting information from arti- ficial neural networks, but categorizing them as symbolic knowledge have been little explored. The obstacle lies on the difficulty to find logical justification from response patterns of these networks [2]. This gets worse when considering induc- tive learning from dynamic data which is very important to Cognitive Sciences that considers categorization as a mental operation of classifying objects, actions and events [1]. We shall address the discoveries of our on-going investigation on the problem of inductively learning (IL) from dynamic data by applying a novel framework for neural-symbolic representation and reasoning called share Neural Multi-Space (NeMuS) used in the Amao system[4]. Instead of woking like traditional ap- proaches for ILP, e.g. [5], Amao uses a shared NeMuS of a give background knowledge (BK) and uses inverse unification as the generalization mechanism of a set of logically connected expressions from the Herbrand Base (HB) of BK that defines positive examples
Ellipsoidal configurations in the de Sitter spacetime
The cosmological constant modifies certain properties of large
astrophysical rotating configurations with ellipsoidal geometries, provided the
objects are not too compact. Assuming an equilibrium configuration and so using
the tensor virial equation with we explore several equilibrium
properties of homogeneous rotating ellipsoids. One shows that the bifurcation
point, which in the oblate case distinguishes the Maclaurin ellipsoid from the
Jacobi ellipsoid, is sensitive to the cosmological constant. Adding to that,
the cosmological constant allows triaxial configurations of equilibrium
rotating the minor axis as solutions of the virial equations. The significance
of the result lies in the fact that minor axis rotation is indeed found in
nature. Being impossible for the oblate case, it is permissible for prolate
geometries, with zero and positive. For the triaxial case, however,
an equilibrium solution is found only for non-zero positive . Finally,
we solve the tensor virial equation for the angular velocity and display
special effects of the cosmological constant there.Comment: 15 pages, 11 figures, published in Class. Quant. Grav. References
adde
Outbreak of Clostridium difficile PCR ribotype 027-the recent experience of a regional hospital
Background: Clostridium difficile infection (CDI) is the leading cause of healthcare-associated diarrhea, and several
outbreaks with increased severity and mortality have been reported. In this study we report a C. difficile PCR
ribotype 027 outbreak in Portugal, aiming to contribute to a better knowledge of the epidemiology of this agent in
Europe.
Methods: Outbreak report with retrospective study of medical records and active surveillance data of all inpatients
with the diagnosis of CDI, from 1st January to 31th December 2012, in a Portuguese hospital. C. difficile isolates were
characterized regarding ribotype, toxin genes and moxifloxin resistance. Outbreak control measures were taken,
concerning communication, education, reinforcement of infection control measures, optimization of diagnosis and
treatment of CDI, and antibiotic stewardship.
Results: Fifty-three inpatients met the case definition of C. difficile-associated infection: 55% males, median age was
78.0 years (interquartile range: 71.0-86.0), 75% had co-morbidities, only 15% had a nonfatal condition, 68% had at
least one criteria of severe disease at diagnosis, 89% received prior antibiotherapy, 79% of episodes were nosocomial.
CDI rate peak was 13.89/10,000 bed days. Crude mortality rate at 6 months was 64.2% while CDI attributable cause
was 11.3%. Worse outcome was related to older age (P = 0.022), severity criteria at diagnosis (leukocytosis (P = 0.008)
and renal failure), and presence of fatal underlying condition (P = 0.025). PCR ribotype 027 was identified in 16 of 22
studied samples.
Conclusions: This is the first report of a 027-CDI outbreak in Portugal. We emphasize the relevance of the measures
taken to control the outbreak and highlight the importance of implementing a close and active surveillance of CDI
Revealing the structure of the outer disks of Be stars
Context. The structure of the inner parts of Be star disks (20 stellar radii)
is well explained by the viscous decretion disk (VDD) model, which is able to
reproduce the observable properties of most of the objects studied so far. The
outer parts, on the ther hand, are not observationally well-explored, as they
are observable only at radio wavelengths. A steepening of the spectral slope
somewhere between infrared and radio wavelengths was reported for several Be
stars that were previously detected in the radio, but a convincing physical
explanation for this trend has not yet been provided. Aims. We test the VDD
model predictions for the extended parts of a sample of six Be disks that have
been observed in the radio to address the question of whether the observed
turndown in the spectral energy distribution (SED) can be explained in the
framework of the VDD model, including recent theoretical development for
truncated Be disks in binary systems. Methods. We combine new multi-wavelength
radio observations from the Karl. G. Jansky Very Large Array (JVLA) and Atacama
Pathfinder Experiment (APEX) with previously published radio data and archival
SED measurements at ultraviolet, visual, and infrared wavelengths. The density
structure of the disks, including their outer parts, is constrained by
radiative transfer modeling of the observed spectrum using VDD model
predictions. In the VDD model we include the presumed effects of possible tidal
influence from faint binary companions. Results. For 5 out of 6 studied stars,
the observed SED shows strong signs of SED turndown between far-IR and radio
wavelengths. A VDD model that extends to large distances closely reproduces the
observed SEDs up to far IR wavelengths, but fails to reproduce the radio SED.
... (abstract continues but did not fit here)Comment: 20 pages, 8 figure
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