244 research outputs found
Tomographic Simulations of Accretion Disks in Cataclysmic Variables - Flickering and Wind
Both continuum and emission line flickering are phenomena directly associated
with the mass accretion process. In this work we simulate accretion disk
Doppler maps including the effects of winds and flickering flares. Synthetic
flickering Doppler maps are calculated and the effect of the flickering
parameters on the maps is explored. Jets and winds occur in many astrophysical
objects where accretion disks are present. Jets are generally absent among the
cataclysmic variables (CVs), but there is evidence of mass loss by wind in many
objects. CVs are ideal objects to study accretion disks and consequently to
study the wind associated with these disks. We also present simulations of
accretion disks including the presence of a wind with orbital phase resolution.
Synthetic H-alpha line profiles in the optical region are obtained and their
corresponding Doppler maps are calculated. The effect of the wind simulation
parameters on the wind line profiles is also explored. From this study we
verified that optically thick lines and/or emission by diffuse material into
the primary Roche lobe are necessary to generate single peaked line profiles,
often seen in CVs. The future accounting of these effects is suggested for
interpreting Doppler tomography reconstructions.Comment: 9 pages, 9 figure
Plants biodiversity in olive orchards and surrounding landscapes from a conservation biological control approach
Many natural control agents of olive pests need pollen and nectar from non-crop plants in order to complete their life cycles. However, a deep knowledge about the occurring plant species in the agroecosystem is necessary to select the plant species to be maintained or enhanced from a conservation biological control approach. Thus, in this study, the goal was to increase the understanding about the plants’ biodiversity in an important olive-producing region in the northeast of Portugal. For that, on a weekly basis during the spring and every other week in the summer and autumn, blooming plant inventories were accomplished in three olive orchards with spontaneous vegetation and its surroundings (woody and herbaceous vegetation areas) from April to December of 2012 and 2013. The percentage ground cover for each flowering plant species was recorded following the Daubenmire cover scale modified by Bailey. A total of 258 plant species belonging to 47 families were identified. The most abundant family was Asteraceae, followed by Poaceae, Fabaceae and Brassicaceae. Several species were specific to each land use and presented different flowering periods, representing a potential variety of food sources across the seasons. Additionally, some of the identified species are known for their implications as providers of the key requisites for natural control agents. These results provided us with valuable information for the implementation of conservation biological control measures.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal)
for financial support by national funds FCT to CIMO (UIDB/00690/2020). National funding by FCT, through the individual postdoc grant (SFRH/BPD/119487/2016) (María Villa).info:eu-repo/semantics/publishedVersio
Braidings of Tensor Spaces
Let be a braided vector space, that is, a vector space together with a
solution of the Yang--Baxter equation.
Denote . We associate to a solution
of the Yang--Baxter equation on
the tensor space . The correspondence is functorial with respect to .Comment: 10 pages, no figure
Diversidade de plantas da cobertura vegetal herbácea do olival e sua correlação com a diversidade de artrópodes
A vegetação herbácea do olival representa um potencial habitat para a
artropodofauna auxiliar como fonte de alimento (pólen, néctar, meladas ou
presas/hospedeiros alternativos) e abrigo. O objetivo deste trabalho foi estudar a
relação entre a diversidade de plantas da cobertura vegetal herbácea do olival e a
diversidade de artópodes existentes nessas plantas. Numa primeira fase, o estudo
decorreu num olival (Valbom-dos-Figos) onde se realizou a colheita de plantas da
cobertura vegetal herbácea ao longo de 20 transectos formados por uma
circunferência de 1,5 m de raio, colocados na entrelinha e na linha de plantação. Os
artrópodes foram recolhidos com recurso a uma rede de mão. Os espécimes
recolhidos foram identificados à família ou, sempre que possível, à espécie. Numa
segunda fase, utilizou-se a mesma metodologia de amostragem em três olivais
(Valbom-dos-Figos, Paradela e Cedães). Na análise de dados, a biodiversidade de
plantas e de artrópodes foram relacionadas através de uma análise canónica com a
finalidade de detetar potenciais associações entre plantas e artrópodes. As famílias de
plantas mais representadas foram Poaceae, Fabaceae e Asteraceae. Na linha de
plantação destacou-se a família Poaceae, enquanto na entrelinha as famílias mais
representadas foram Poaceae e Fabaceae. Em Paradela foi identificado um maior
número de famílias quando comparado com Cedães e Valbom dos Figos.
Relativamente aos artrópodes, Aphidide, Diptera e Thysanoptera foram as ordens mais
abundantes com uma abundância relativa de 37,2%, 34,9% e 13,0%, respetivamente.
Tanto estas ordens, como as ordens Araneae e Coleoptera registaram maiores
abundâncias na linha de plantação do que na entrelinha. O grupo dos parasitóides
revelou uma riqueza de 18 famílias, sendo as famílias Braconidae, Ichneumonidae e
Eulophidae as mais abundantes. A análise canónica revelou elevada correlação entre
as famílias Braconidae e Asteraceae e entre duas espécies de formigas (Crematogaster
scutellaris e Tapinoma nigerrimum) e plantas da família Fabacea
Biodiversity and pollen feeding habits of syrphids in olive groves and surrounding landscape in Northeastern Portugal during spring
Many syrphid larvae are predators of aphids and early stages of moths and psyllids, being potential control agents of some olive pests. However, adults need pollen and nectar for energy and reproduction. An increase of plant resources biodiversity in heterogeneous landscape could benefit these natural enemies. Thus, our goal of was to study the syrphid biodiversity and their pollen sources in olive agroecosystems from the northeast of Portugal during spring, that coincides with the availability of pests. For that, syrphids were captured in three not-tilled olive groves and two surrounding field areas (an herbaceous vegetation patch and a scrubland) next to each olive grove. Simultaneously, flowering plant inventories were carried out. Syrphids and the pollen contained in the guts of the most abundant species were identified. Thereafter pollen in guts was compared with pollen in the environment to evaluate a potential pollen selection. The most abundant species were Sphaerophoria scripta and Melanostoma mellinum. During the spring syrphids did not consume all the occurring plant species but did not actively selected pollen types. Results indicated that Asteraceae, Plantaginaceae, Caryophyllaceae, Echium type, Rumex type and Jasione type are important food sources for M. mellinum and S. scripta. These results will allow managing ground cover vegetation more efficiently in order to conserve syrphids in the olive agroecosystem.M. Villa is grateful to the Foundation for Science and Technology (Portugal) for the postdoctoral grant SFRH/BPD/119487/2016info:eu-repo/semantics/publishedVersio
Biodiversity and pollen feeding habits of syrphids in olive groves and surrounding landscape in Northeastern Portugal during spring
info:eu-repo/semantics/publishedVersio
Pollen feeding by syrphids varies across seasons in a Mediterranean landscape dominated by the olive orchard
Syrphids provide valuable ecosystem services such as pollination, pest control or organic matter decomposition.
In many cases, adults exploit pollen resources from the landscape to complete their life cycles. Yet, the
knowledge about the most suitable plants for enhancing syrphid populations is still insufficient for most habitats.
Also syrphid distribution across the landscape is understudied. In this work we analyzed: (i) syrphids distribution
across different land uses and seasons in a Mediterranean landscape dominated by olive orchards, (ii) pollen
resources exploited by the most abundant syrphid species and (iii) specific pollen resources relevant for egg
production. Syrphids were captured weekly in spring, summer and autumn from April to November 2013 with a
sweep net in patches with different land uses (olive orchards, herbaceous and scrubland patches). Nine species,
generally with predatory aphidophagous larvae, were identified. The most abundant species was Sphaerophoria
scripta (L.) followed by Melanostoma mellinum (L.). Sphaerophoria scripta was associated to olive orchards while
M. mellinum was associated to herbaceous/scrubland patches. Pollen selection and consumption and number of
eggs within gravid females for the most abundant species were determined through gut dissection and identified
with a microscope. Several pollen types were showed a positive selection index by syrphid species. During spring
and summer, the most ingested pollen types belonged to abundant plants in the patches of capture indicating that
syrphids possibly do not need to fly among patches to feed during those periods. In spring, Asteraceae and
Plantago type were particularly consumed by S. scripta and M. mellinum gravid females respectively while in
summer feeding habits of males, gravid and non-gravid females did not differ. Females consumed more pollen
than males but the number of eggs in gravid females was not related with the amount of ingested pollen grains.
This study brings some insights about the seasonal variation of pollen feeding habits shown by adult syrphids
across a Mediterranean heterogeneous landscape dominated by the olive orchard. In spring, dense flowering
strips maintained within the olive orchards might attract and nourish adult syrphids while in summer syrphids
might fly to non-crop areas to feedinfo:eu-repo/semantics/publishedVersio
Daily living activities in Parkinson's disease patients underwent to stereotactic surgery
OBJECTIVE: To evaluate the impact of stereotactic surgery on daily activities of Parkinson's disease (PD) patients. METHOD: Thirty patients with idiopathic PD were evaluated before surgery and one, three, six and twelve months after surgery. Patients were evaluated with the UPDRS - part II (Unified Parkinson's Disease Rating Scale) and the Schwab & England scales. Nine of the patients had also been evaluated after twenty four months. RESULTS: We performed nine posteroventral pallidotomies (PVP), two on the left hemisphere and seven on the right; 17 ventrolateral thalamotomies (VLT), 12 on the left and five on the right; two VLT on the left associated with PVP on the right at the same surgical procedure. The mean off phase scores of Schwab & England scale were: 60.6 before surgery, 74 after the first, 76.6 after the third, 75.6 after the sixth, 72.3 after the twelfth and 71.1 after the twenty fourth months after surgery. The mean off phase scores of UPDRS - part II scale were: 21 before surgery, 12.3 after the first, 14.7 after the third, 15.27 after the sixth, 17.1 after the twelfth and 17.5 after the twenty fourth months after surgery. CONCLUSION: VTL and PVP are useful procedures to improve daily living activities of the PD patients and the best results are seen by six months after surgery.OBJETIVO: Avaliar o impacto da cirurgia estereotáxica sobre a realização das atividades da vida diária dos paciente com doença de Parkinson (DP). MÉTODO: Foram avaliados 30 pacientes com DP forma idiopática submetidos a cirurgia estereotáxica nos períodos pré-operatório, 1º, 3º, 6º e 12º mês pós-operatório, segundo as escala UPDRS - Item II (escala unificada para DP), Schwab & England e Hoehn & Yahr. Destes, nove pacientes foram também avaliados no 24º mês pós-operatório. RESULTADOS: Foram realizadas nove palidotomias póstero-ventrais (PPV), sendo duas à esquerda e sete à direita; duas PPV bilaterais no mesmo tempo cirúrgico; 17 talamotomias ventro-laterais (TVL), sendo 12 à esquerda e cinco à direita; duas TVL à esquerda com PPV à direita no mesmo tempo cirúrgico. Os escores médios, na fase off, das escalas utilizadas foram: 65,6 no pré-operatório,74 no 1º mês, 76,6 no 3º mês, 75,6 no 6º mês e 72,3 no 12º mês pós-operatório (Schwab & England); 21 no pré-operatório, 12,3 no 1º mês, 14,7 no 3º mês, 15,27 no 6º mês e 17,1 no 12º mês pós-operatório (UPDRS); 3,1 no pré-operatório, 2,8 no 1º mês, 2,7 no 3º mês, 2,8 no 6º mês e 2,85 no 12º mês pós-operatório (Hoehn & Yarh). CONCLUSÃO: A TVL e a PPV são procedimentos capazes de melhorar a independência dos pacientes para realização das atividades cotidianas, sendo constatado benefício maior nos seis primeiros meses de pós-operatório.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de NeurologiaUNIFESP, EPM, Depto. de NeurologiaSciEL
Habitat structure and neighbor linear features influence more carabid functional diversity in olive groves than the farming system
The effects of land-use management and environmental features at different scales on carabid beetle diversity and trait structure were assessed across olive groves in northeastern Portugal. We selected organic and integrated olive groves that were distinct in terms of specific management practices, local linear features and landscape configurations. Besides the management intensification levels, differences in carabid diversity and community traits were mainly due to local habitat and ecological linear structures at a finer spatial scale. Carabid community traits related to disturbance, namely traits of body size and species dispersal ability, responded to land-use intensity and particular olive grove features were influencing diversity patterns. Within the olive grove patches, larger and brachypterous species were associated to plots with more dense vegetation cover while macropterous and small-sized species were more associated to open areas. Also, larger carabid species benefitted from higher patch size heterogeneity within the landscape mosaics. Our findings indicate that the effects of farming system is contingent on the specific management practices, local and linear features present in agroecosystems such as olive groves. Particularly, the influence of local features on carabid diversity patterns and community traits linked to dispersal and movement may be crucial in maintaining pest control at a landscape scale.The authors would like to thank all farmers who allowed our access
to their olive groves. This work and the writing of this manuscript was
funded by Portuguese Foundation for Science and Technology (FCT)
through the project PTDC/AGR-PRO/111123/2009 (The use of biological indicators as tools for assessing the impact of agricultural practices
in sustainability of olive grove) and the project BiodivERsA/001/2014
(ECOSERVE − Sustainable provisioning of multiple ecosystem services
in agricultural landscapes). P. Martins da Silva was supported by the
Portuguese Foundation for Science and Technology (SFRH/BPD/
109511/2015). The authors are indebted to two anonymous reviewers
who helped to improve a previous version of this study.info:eu-repo/semantics/publishedVersio
Indirect evaluation of pit and fissure sealants : a 3D-based method validation
The aim of the present study was to compare indirect methods to assess the clinical performance of pit and fissure sealants and validate the use of 3D scanners. Sample consisted of 58 plaster models of upper and lower first permanent molars, sealed with resin sealants, as well as photographs obtained during the 18-month follow-up. Pre-established criteria were applied to categorize the sealant presence/absence and marginal integrity. Two calibrated examiners performed the evaluations, independently, using Scanning Electron Microscopy (SEM; gold-standard), Photography, 3D (CEREC In Lab) and Stereomicroscope analysis. The intra-examiner Spearman correlation was 94% e 97%, respectively, and the inter-examiner was 96%. Data was submitted to Kappa test, Spearman correlation and Receiver Operating Characteristic Curve (ROC). 3D and SEM presented good concordance; Stereomicroscope showed regular concordance with SEM and 3D (p0.05). SEM had a significant positive correlation with 3D and Stereomicroscope (r=0.76 and 0.71, respectively; p<0.01). There was significant positive correlation (r=0.65) between 3D and Stereomicroscope (p<0.01). The ROC estimated curve areas for Stereomicroscope and 3D were 0.90 (IC:0.81-0.99) and 1.0 (IC:1.0-1.0), respectively (p<0.001). Photography presented lower sensitivity and specificity (area=0.59). 3D method showed the best performance when compared to gold standard, exhibiting high sensitivity and specificity, therefore, it was validated as a reliable method to evaluate pit and fissure sealants
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