274 research outputs found
Myxoid fibroblastic tumor of the maxillary sinus in a 21-month-old child: an unusual diagnosis
Myxoid tumors of the soft tissue are a heterogeneous group of lesions with significant differences in behavior, from being totally harmless to malignant tumors with metastasizing potential. We describe the unusual case of a 21-month-old boy who developed a paranasal low-grade myxoid neoplasm with recurrent potential. The histological findings showed a proliferation of spindle cells within a vascular and myxoid background. The immunohistochemistry had the features of myofibroblasts and fibroblasts with strong Vimentin and light Smooth Muscle Actin reactivity. Close collaboration between clinician and pathologist is necessary to deal with these unusual lesions to predict their local aggressiveness and long-term behavior. Most of these cellular myxomas have been described in adults, involving primarily the limbs, but this case shows that any localization is possibl
Towards a computer aided diagnosis system dedicated to virtual microscopy based on stereology sampling and diffusion maps
An original strategy is presented, combining stereological sampling methods based on test grids and data reduction methods based on diffusion maps, in order to build a knowledge image database with no bias introduced by a subjective choice of exploration areas. The practical application of the exposed methodology concerns virtual slides of breast tumors
Update of the Scientific Opinion on the risks to plant health posed by Xylella fastidiosa in the EU territory
EFSA was asked to update the 2015 EFSA risk assessment on Xylella fastidiosa for the territory of the EU. In particular, EFSA was asked to focus on potential establishment, shortâ and longârange spread, the length of the asymptomatic period, the impact of X. fastidiosa and an update on risk reduction options. EFSA was asked to take into account the different subspecies and Sequence Types of X. fastidiosa. This was attempted throughout the scientific opinion but several issues with data availability meant that this could only be partially achieved. Models for risk of establishment showed most of the EU territory may be potentially suitable for X. fastidiosa although southern EU is most at risk. Differences in estimated areas of potential establishment were evident among X. fastidiosa subspecies, particularly X. fastidiosa subsp. multiplex which demonstrated areas of potential establishment further north in the EU. The model of establishment could be used to develop targeted surveys by Member States. The asymptomatic period of X. fastidiosa varied significantly for different host and pathogen subspecies combinations, for example from a median of approximately 1 month in ornamental plants and up to 10 months in olive, for pauca. This variable and long asymptomatic period is a considerable limitation to successful detection and control, particularly where surveillance is based on visual inspection. Modelling suggested that local eradication (e.g. within orchards) is possible, providing sampling intensity is sufficient for early detection and effective control measures are implemented swiftly (e.g. within 30 days). Modelling of longârange spread (e.g. regional scale) demonstrated the important role of longârange dispersal and the need to better understand this. Reducing buffer zone width in both containment and eradication scenarios increased the area infected. Intensive surveillance for early detection, and consequent plant removal, of new outbreaks is crucial for both successful eradication and containment at the regional scale, in addition to effective vector control. The assessment of impacts indicated that almond and Citrus spp. were at lower impact on yield compared to olive. Although the lowest impact was estimated for grapevine, and the highest for olive, this was based on several assumptions including that the assessment considered only Philaenus spumarius as a vector. If other xylemâfeeding insects act as vectors the impact could be different. Since the Scientific Opinion published in 2015, there are still no risk reduction options that can remove the bacterium from the plant in open field conditions. Shortâ and longârange spread modelling showed that an early detection and rapid application of phytosanitary measures, consisting among others of plant removal and vector control, are essential to prevent further spread of the pathogen to new areas. Further data collection will allow a reduction in uncertainty and facilitate more tailored and effective control given the intraspecific diversity of X. fastidiosa and wide host range.Additional co-authors: EFSA Panel on Plant Health (PLH), Wopke van der Werf, Antonio Vicent Civera, Jonathan Yuen, Lucia ZappalĂ , Donato Boscia, Gianni Gilioli, Rodrigo Krugner, Alexander Mastin, Anna Simonetto, Joao Roberto Spotti Lopes, Steven White, JosĂ© Cortinas Abrahantes, Alice Delbianco, Andrea Maiorano, Olaf MosbachâSchulz, Giuseppe Stancanelli, Michela Guzzo, Stephen Parnel
Pest categorisation of Conotrachelus nenuphar
The EFSA Panel on Plant Health performed a pest categorisation of Conotrachelus nenuphar (Herbst)
(Coleoptera: Curculionidae), for the EU. C. nenuphar is a well-defined species, recognised as a serious
pest of stone and pome fruit in the USA and Canada where it also feeds on a range of other hosts
including soft fruit (e.g. Ribes, Fragaria) and wild plants (e.g. Crataegus). Adults, which are not good
flyers, feed on tender twigs, flower buds and leaves. Females oviposit into host fruit; if oviposition
occurs in young fruit, the fruit usually falls prematurely reducing yield; oviposition in older fruit causes
surface blemishes and the fruit distorts as it develops reducing marketability. Larvae develop within
host fruit but exit to pupate in soil. Adults overwinter in leaf litter. C. nenuphar is not known to occur
in the EU and is listed in Annex IAI of Council Directive 2000/29/EC. Fruit infested shortly before
harvest and soil with leaf litter accompanying plants for planting could potentially provide a pathway
into the EU. Considering the climatic similarities between North America and Europe, and that hosts
occur widely within the EU, C. nenuphar has potential to establish within the EU. There could be one
or two generations per year, as in North America. Impacts could be expected, e.g. in Prunus spp. and
apples. Phytosanitary measures are available to reduce the likelihood of introduction of C. nenuphar.
All of the criteria assessed by EFSA for consideration as a potential Union quarantine pest are met.
C. nenuphar does not meet the criteria of occurring in the EU nor plants for planting being the
principal means of spread. Hence it does not satisfy all of the criteria that are within the remit of EFSA
to assess for it to be regarded as a Union regulated non-quarantine pest (RNQP)
Pest categorisation of Sternochetus mangiferae
The European Commission requested EFSA to conduct a pest categorisation of Sternochetus mangiferae
(Coleoptera: Curculionidae), a monophagous pest weevil whose larvae exclusively feed on mango seeds,
whereas adults feed on mango foliage. S. mangiferae is a species with reliable methods available for
identification. It is regulated in the EU by Council Directive 2000/29/EC where it is listed in Annex IIB as a
harmful organism whose introduction into EU Protected Zones (PZ) (Alentejo, Algarve and Madeira in
Portugal, and Granada and Malaga in Spain) is banned. S. mangiferae is native to South East Asia and
has spread to other mango-growing areas in Africa, South America and Oceania, causing significant
damage. Larvae of S. mangiferae have been detected several times in mango fruit imported into the EU.
In 2013, an outbreak was declared in one PZ in Spain. Official measures taken achieved eradication,
which was officially declared in January 2018. The EFSA Plant Health Panel concludes that S. mangiferae
could establish again and spread in the mango-growing areas of southern EU. Considering the criteria
within the remit of EFSA to assess the status as a potential Union quarantine pest (QP), as a potential
protected zone quarantine pest (PZQP) or as a potential regulated non-quarantine pest (RNQP),
S. mangiferae meets with no uncertainties the criteria for consideration as a potential Union QP, as it is
absent from the EU, potential pathways for entry exist, and its establishment would cause an economic
impact. The criterion of the pest being present in the EU, which is a prerequisite for RNQP and PZ QP, is
not met
Pest categorisation of Acrobasis pirivorella
The European Commission requested EFSA to conduct a pest categorisation of Acrobasis pirivorella
(Lepidoptera: Pyralidae), a monophagous moth whose larvae exclusively feed on developing buds,
flowers, and fruits of cultivated and wild Pyrus spp. A. pirivorella is a species with reliable methods
available for identification. A. pirivorella occurs in north-east Asia only, causing significant damage in
cultivated pears. It is regulated in the EU by Council Directive 2000/29/EC where it is listed in Annex IIAI.
Within this regulation, plants for planting of Pyrus spp. is a closed pathway. This species has never been
reported by Europhyt. Fruits and cut branches of Pyrus spp. are open pathways. Biotic and abiotic
conditions are conducive for establishment and spread of A. pirivorella in the EU. Were A. pirivorella to
establish, impact on pear production is expected. Considering the criteria within the remit of EFSA to
assess its regulatory plant health status, A. pirivorella meets the criteria for consideration as a potential
Union quarantine pest (it is absent from the EU, potential pathways exist and its establishment would
cause an economic impact). Given that A. pirivorella is not known to occur in the EU, it fails to meet some
of the criteria required for regulated non-quarantine pest (RNQP) status
Pest categorisation of Scaphoideus luteolus
The Panel on Plant Health performed a pest categorisation of Scaphoideus luteolus, a well-defined
phloem sap-feeding insect species in the family Cicadellidae (Insecta: Hemiptera). It can be identified
using taxonomic keys. S. luteolus is only present in the eastern part of the USA. The main host plants of
S. luteolus are species of the genus Ulmus (U. americana, U. alata, U. bergmanianna, U. szechuanica,
U. rubra), but specimens have also been collected on Vitis sp., Salix sp. and Populus sp. The species does
not cause damage by itself, but it is the only confirmed vector of the phytoplasma Candidatus
Phytoplasma ulmi (CPu), which is present in North America where it causes heavy damage to the local
elms, as well as in some European countries where the local elms are considered less susceptible.
S. luteolus has three developmental stages (egg, nymph, adult). It overwinters in the egg stage, takes
36â42 days to complete nymphal stage, and adults are found throughout the summer period. Both
nymphs and adults are capable of transmitting CPu and, after acquiring the pathogen, remain infective
for the rest of their life. The main pathways are cut branches and plants for planting. These pathways are
not regulated for the main host, Ulmus, though requirements are in place in relation to other pests on
Ulmus. These pathways are also not regulated for Salix. Establishment would be favoured by the wide
coverage of Ulmus spp. in the EU territory and by climatic conditions comparable to those of the pestâs
native range. S. luteolus meets all the criteria assessed by EFSA for consideration as potential Union
quarantine pest. The criteria for considering it as a potential Union regulated non-quarantine pest are not
met since the species is absent from the EU
Pest categorisation of Aleurocanthus spp
The Panel on Plant Health performed a pest categorisation of
Aleurocanthus
spp., a well-de
fi
ned insect
genus of the white
fl
y family Aleyrodidae (Arthropoda: Hemiptera). Dif
fi
culties within the taxonomy of
the genus give doubt about the ability to accurately identify some members to species level.
Nevertheless, the genus is thought to currently include about ninety species mainly reported from
tropical and subtropical areas. The genus is listed in Council Directive 2000/29/EC and is regulated on
Citrus, Fortunella
and
Poncirus
. Several
Aleurocanthu
s species are highly polyphagous;
Aleurocanthu
s
spiniferus
has hosts in 38 plant families;
Aleurocanthu
s
woglumi
has more than 300 hosts including
Pyrus
,
Rosa
and
Vitis vinifera
as well as
Citrus
.
A. spiniferus
is present in the EU in restricted areas of
Italy and Greece, where it is under of
fi
cial control. No other
Aleurocanthus
spp. are known to occur in
the EU. Host plants for planting, excluding seeds, and cut
fl
owers or branches are the main pathways
for entry. Outside of the EU, the genus can be found in regions that have climate types which also
occur within the EU, suggesting establishment is possible.
Aleurocanthus
spp. can be signi
fi
cant pests
of crops that are also grown in the EU. Phytosanitary measures are available to reduce the likelihood
of entry into the EU, e.g. sourcing host plants for planting from pest free areas. As a genus
Aleurocanthus
does satisfy all the criteria that are within the remit of EFSA to assess and required by
risk managers to give it consideration as a Union quarantine pest.
Aleurocanthus
does not meet all of
the criteria to allow it consideration by risk managers as a Union regulated non-quarantine pest
(RNQP). Speci
fi
cally,
Aleurocanthus
is not widespread in the EU
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