825 research outputs found
The buccal mucosa fenestrated graft for Bracka first stage urethroplasty: experimental study in rabbits
Objective To histologically evaluate, in an experimental study in rabbits, the integration process of the buccal mucosa fenestrated graft applied in the corpora cavernosa for Bracka first stage urethroplasty. Materials and Methods A urethral defect was surgically created in 16 male rabbits of the New Zealand breed through the excision of the penile urethra. The urethral defect was corrected by applying buccal mucosa fenestrated graft through two cruciform incisions in the distal portions of its longitudinal axis. The animals were sacrificed at 2, 4, 8 and 12 weeks post surgery and their genitals were subjected to clinical and histological assessment. Results The buccal mucosa fenestrated graft showed complete uptake in all groups, with keratinization squamous metaplasia and mucosal proliferation of the fenestrated areas. The fenestrated graft area represented an increase in length of 25% in length in relation to the original standard graft. Conclusions The fenestrated buccal mucosa graft presented total integration to the adjacent epithelia with re-epithelization of the incision areas of the graft (fenestrations) and no significant inflammatory or scarring reactions when compared to other mucosa transplanted areas; therefore its application is viable in cases of extensive urethral defect whenever the donating area might be insufficient.Federal University of São Paulo Departament of Urology (PO, HB, AR, UBjr, VO, AMjr) Department of Pathology (RD)UNIFESP, Departament of Urology (PO, HB, AR, UBjr, VO, AMjr) Department of Pathology (RD)SciEL
K band Spectroscopy of Ultraluminous Infrared Galaxies: The 2 Jy Sample
We present near-infrared spectroscopy for a complete sample of 33
ultraluminous infrared galaxies at a resolution of R\approx 1000. Most of the
wavelength range from 1.80-2.20 microns in the rest frame is covered, including
the Pa-alpha and Br-gamma hydrogen recombination lines, and the molecular
hydrogen vibration-rotation 1-0 S(1) and S(3) lines. Other species, such as He
I, [Fe II], and [Si VI] appear in the spectra as well, in addition to a number
of weaker molecular hydrogen lines. Nuclear extractions for each of the
individual galaxies are presented here, along with spectra of secondary nuclei,
where available. The Pa-alpha emission is seen to be highly concentrated on the
nuclei, typically with very little emision extending beyond a radius of 1 kpc.
Signatures of active nuclei are rare in the present sample, occurring in only
two of the 33 galaxies. It is found that visual extinctions to the nuclei via
the Pa-alpha/Br-gamma line ratio in excess of 10 magnitudes are relatively
common among ULIRGs, and that visual extinctions greater than 25 mag are
necessary to conceal a QSO emitting half the total bolometric luminosity. The
vibration-rotation lines of molecular hydrogen appear to be predominantly
thermal in origin, with effective temperatures generally around 2200 K. The
relative nuclear velocities between double nucleus ULIRGs are investigated,
through which it is inferred that the maximum deprojected velocity difference
is about 200 km/s. This figure is lower than the velocities predicted by
physical models of strong interactions/mergers of large, gas-rich galaxies.Comment: 52 pages (19 with just figures), 9 figures, accepted for publication
in the Astronomical Journal; Table 3 not formatted properly on astro-ph: get
source and print Murphy.tab3.p
The Active Nucleus in the Ultraluminous Infrared Galaxy IRAS 08311-2459
Near-infrared spectroscopy using the new Palomar Integral Field Spectrograph
indicates the presence of an AGN (active galactic nucleus) in the ultraluminous
infrared galaxy IRAS 08311-2459. The high-velocity wings of the Paschen-alpha
hydrogen recombination line are seen to be spatially unresolved, and with no
positional offset between red and blue high velocity emission. The [Si VI]
coronal line, with a 167 eV excitation potential, is also spatially unresolved
with a velocity width comparable to that of the broad component of the Pa-alpha
emission. The low velocity component of the Pa-alpha emission is seen to be
rotating, and is extended over about 2 kpc. Molecular hydrogen is also
extended, and elongated along the maximum velocity gradient, sharing the same
rotation profile as the narrow Pa-alpha emission. The simple picture in
agreement with the observations is that of an AGN surrounded by a rotating disk
of star formation. These observations lend strength to the usage of [Si VI] as
a diagnostic of AGN activity in ultraluminous infrared galaxies, and also
highlight the utility of integral field spectroscopy in elucidating subtle
morphological differences in line emitting regions.Comment: 18 pages, 7 figures (fig. 7 color), AASTeX v5.0, accepted for publ.
in A
Unsupervised classemes
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-33885-4_41Proceedings of Information Fusion in Computer Vision for Concept Recognition at the ECCV 2012In this paper we present a new model of semantic features that, unlike previously presented methods, does not rely on the presence of a labeled training data base, as the creation of the feature extraction function is done in an unsupervised manner.
We test these features on an unsupervised classification (clustering) task, and show that they outperform primitive (low-level) features, and that have performance comparable to that of supervised semantic features, which are much more expensive to determine relying on the presence of a labeled training set to train the feature extraction function
Instabilidade de microsatelites no cancer gástrico solitário e esporádico
Recently, the presence of microsatellite instability (MSI) has been reported in gastric cancer and associated with older age of presentation, distal tumor location, early disease staging, and better overall prognosis. Different characteristics in presentation and in tumor behavior may be explained by different genetic alterations during carcinogenesis of gastric cancer. Identification of specific genetic pathways in gastric cancer may have direct impact on prognosis and selection of treatment strategies. PATIENTS AND METHODS: All 24 patients were treated by radical surgery. Fragments of normal and tumor tissues were extracted from the specimen and stored at -80ºC before DNA purification and extraction. PCR amplification utilizing microsatellite markers was performed. Tumors presenting PCR products of abnormal sizes were considered positive for microsatellite instability (MSI+). RESULTS: Five patients (21%) had tumors that were MSI+ in at least 1 marker. In the group of patients with Lauren's intestinal-type gastric carcinoma, 3 had tumors that were MSI+ (23%), while in the group of diffuse-type gastric cancer, 2 patients had tumors that were MSI+ (19%). The mean age of presentation and the male:female ratio was similar in both groups. Tumors that were MSI+ were more frequently located in proximal portion of the stomach compared to microsatellite-stable (MSS) tumors (40% vs. 16%). Although there was a trend of patients with MSI+ tumors towards a proximal gastric tumor location, early staging, and negative lymph node metastasis, there was no statistical significance compared to those with MSS tumors (P >;.1). Comparison of overall and disease-free survival between gastric tumors that were MSI+ and those that were MSS found no statistically significant differences (P >;.1). CONCLUSIONS: Microsatellite instability is a frequent event in gastric carcinogenesis and shows a trend towards distinct clinical and pathological characteristics of gastric cancer.A presença de Instabilidade de microsatellites (IMS) tem sido relatada no cancer gastrico e associada a pacientes com idade mais avançada, localização mais distal do tumor, estadios mais precoces e melhor prognostico. Relatamos neste prospectivo estudo envolvendo 24 pacientes com cancer gastrico solitario e esporadico, a incidencia de IMS, sua correlação com parametros epidemiologicos, clinicos e anatomo patológicos e o seu impacto sobre a sobrevida geral e livre de doença. PACIENTES E MÉTODOS: Todos os pacientes haviam sido tratados com cirurgia radical. Fragmentos de tecido normal e tumoral eram extraidos das peças e armazenados a -80ºC antes da extração e purificação DNA. Realizava-se então a amplificação com PCR utilizando marcadores específicos de microsatelites. Os tumores que apresentavam produtos de amplificação anormais foram considerados positivos para IMS. RESULTADOS: Cinco pacientes (21%) apresentaram Instabilidade de microsatelites (IMS+) com pelo menos um marcador (primer) No grupo de pacientes com adenocarcinomas gástricos do tipo histológico de Lauren, três apresentavam IMS (23%) enquanto no grupo portador de cancar gástrico difuso, dois pacientes mostraram IMS (19%).. Embora haja uma tendência dos pacientes IMS+ apresentarem tumores de localização mais proximal, estadios mais precoces e ausência de metástases linfonodais, não se observou diferenças estatisticamente significativas (p >; 0,1). A comparação entre as taxas de sobrevida geral e livre de doença não mostrou significância estatistica (p >; 0,1). CONCLUSÕES: IMS é um evento frequente na carcinogese gástrica e pode estar associado a caracteristicas clinicas e anátomo-patológicas do câncer gástrico
The granite and glacial landscapes of the Peneda-Gerês National Park
Granite and glacial landforms are presented as the main geomorphological landscape features of the Peneda-Gerês National Park. The park was established in 1971 and it is the only national park and most important protected area in Portugal. The aesthetic attractiveness is supported mainly by the distinct granite landscape of the Gerês and Peneda Mountains, where the post-orogenic Variscan Gerês gran- ite facies occurs. The rugged relief is poorly covered by vegetation, differentiating it from the surrounding moun- tainous areas and the most distinctive landforms are bornhardts, locally named as “medas”. Typical glacial landforms, such as U-shaped valleys, cirques and moraines, express the sheltered character of a low-altitude glaciation, which is of great significance in the context of the Pleistocene glaciation in Southern Europe.This work is co-funded by the European Union
through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Inter nacionalização), project ICT (UID/GEO/04683/2013) with reference
POCI-01-0145- FEDER-007690 and Portuguese national funds pro vided by Fundação para a Ciência e Tecnologi
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Pond dyes are Culex mosquito oviposition attractants
Background
British mosquito population distribution, abundance, species composition and potential for mosquito disease transmission are intimately linked to the physical environment. The presence of ponds and water storage can significantly increase the density of particular mosquito species in the garden. Culex pipiens is the mosquito most commonly found in UK gardens and a potential vector of West Nile Virus WNV, although the current risk of transmission is low. However any factors that significantly change the distribution and population of C. pipiens are likely to impact subsequent risk of disease transmission. Pond dyes are used to control algal growth and improve aesthetics of still water reflecting surrounding planting. However, it is well documented that females of some species of mosquito prefer to lay eggs in dark water and/or containers of different colours and we predict that dyed ponds will be attractive to Culex mosquitoes.
Methods
Black pond dye was used in oviposition choice tests using wild-caught gravid C. pipiens. Larvae from wild-caught C. pipiens were also reared in the pond dye to determine whether it had any impact on survival. An emergence trap caught any adults that emerged from the water. Water butts (80 L) were positioned around university glasshouses and woodland and treated with black pond dye or left undyed. Weekly sampling over a six month period through summer and autumn was performed to quantified numbers of larvae and pupae in each treatment and habitat.
Results
Gravid female Culex mosquitoes preferred to lay eggs in dyed water. This was highly significant in tests conducted under laboratory conditions and in a semi-field choice test. Despite this, survivorship in black dyed water was significantly reduced compared to undyed water. Seasonal analysis of wild larval and pupal numbers in two habitats with and without dye showed no impact of dye but a significant impact of season and habitat. Mosquitoes were more successful, with significantly higher numbers of pupae, in the habitat where they had vegetation cover and shade.
Discussion
Our study has raised some interesting possibilities; one is that where used, pond dyes may be encouraging mosquitoes to breed in gardens in close proximity to people. Considering the concerns over potential future spread of disease in urban environments, this as well as shading of ponds and water butts, should inform future advice over reducing mosquito breeding and spread
Holographic c-theorems in arbitrary dimensions
We re-examine holographic versions of the c-theorem and entanglement entropy
in the context of higher curvature gravity and the AdS/CFT correspondence. We
select the gravity theories by tuning the gravitational couplings to eliminate
non-unitary operators in the boundary theory and demonstrate that all of these
theories obey a holographic c-theorem. In cases where the dual CFT is
even-dimensional, we show that the quantity that flows is the central charge
associated with the A-type trace anomaly. Here, unlike in conventional
holographic constructions with Einstein gravity, we are able to distinguish
this quantity from other central charges or the leading coefficient in the
entropy density of a thermal bath. In general, we are also able to identify
this quantity with the coefficient of a universal contribution to the
entanglement entropy in a particular construction. Our results suggest that
these coefficients appearing in entanglement entropy play the role of central
charges in odd-dimensional CFT's. We conjecture a new c-theorem on the space of
odd-dimensional field theories, which extends Cardy's proposal for even
dimensions. Beyond holography, we were able to show that for any
even-dimensional CFT, the universal coefficient appearing the entanglement
entropy which we calculate is precisely the A-type central charge.Comment: 62 pages, 4 figures, few typo's correcte
Galactic and Extragalactic Samples of Supernova Remnants: How They Are Identified and What They Tell Us
Supernova remnants (SNRs) arise from the interaction between the ejecta of a
supernova (SN) explosion and the surrounding circumstellar and interstellar
medium. Some SNRs, mostly nearby SNRs, can be studied in great detail. However,
to understand SNRs as a whole, large samples of SNRs must be assembled and
studied. Here, we describe the radio, optical, and X-ray techniques which have
been used to identify and characterize almost 300 Galactic SNRs and more than
1200 extragalactic SNRs. We then discuss which types of SNRs are being found
and which are not. We examine the degree to which the luminosity functions,
surface-brightness distributions and multi-wavelength comparisons of the
samples can be interpreted to determine the class properties of SNRs and
describe efforts to establish the type of SN explosion associated with a SNR.
We conclude that in order to better understand the class properties of SNRs, it
is more important to study (and obtain additional data on) the SNRs in galaxies
with extant samples at multiple wavelength bands than it is to obtain samples
of SNRs in other galaxiesComment: Final 2016 draft of a chapter in "Handbook of Supernovae" edited by
Athem W. Alsabti and Paul Murdin. Final version available at
https://doi.org/10.1007/978-3-319-20794-0_90-
Spitzer and JCMT Observations of the Active Galactic Nucleus in the Sombrero Galaxy (NGC 4594)
We present Spitzer 3.6-160 micron images, Spitzer mid-infrared spectra, and
JCMT SCUBA 850 micron images of the Sombrero Galaxy (NGC 4594), an Sa galaxy
with a 10^9 M_solar low luminosity active galactic nucleus (AGN). The brightest
infrared sources in the galaxy are the nucleus and the dust ring. The spectral
energy distribution of the AGN demonstrates that, while the environment around
the AGN is a prominent source of mid-infrared emission, it is a relatively weak
source of far-infrared emission, as had been inferred for AGN in previous
research. The weak nuclear 160 micron emission and the negligible polycyclic
aromatic hydrocarbon emission from the nucleus also implies that the nucleus is
a site of only weak star formation activity and the nucleus contains relatively
little cool interstellar gas needed to fuel such activity. We propose that this
galaxy may be representative of a subset of low ionization nuclear emission
region galaxies that are in a quiescent AGN phase because of the lack of gas
needed to fuel circumnuclear star formation and Seyfert-like AGN activity.
Surprisingly, the AGN is the predominant source of 850 micron emission. We
examine the possible emission mechanisms that could give rise to the 850 micron
emission and find that neither thermal dust emission, CO line emission,
bremsstrahlung emission, nor the synchrotron emission observed at radio
wavelengths can adequately explain the measured 850 micron flux density by
themselves. The remaining possibilities for the source of the 850 micron
emission include a combination of known emission mechanisms, synchrotron
emission that is self-absorbed at wavelengths longer than 850 microns, or
unidentified spectral lines in the 850 micron band.Comment: Accepted to ApJ, 200
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