82 research outputs found
Scientific Report Coincidence of meibomian adenoma and squamous cell carcinoma in the upper eyelid of a sheep: histopathological and immunohistochemical studies
Summary This report is related to a female 7-year-old crossbreed sheep whose right eye had been protruded and swelling of upper eyelid was observed. Routine enucleating was performed. Histopathological evaluation of eyelid revealed coincidence of two kinds of neoplasms. The first part was composed of multiple lobules of sebocytes, which were detected as meibomian adenoma. The second section included infiltrating islands of neoplastic squamous epithelium extending through the basal lamina of the epithelium with keratin pearls and was noted as grade I squamous cell carcinoma. Immunohistochemical study of cytokeratin showed positive reaction in both kinds of neoplastic cells. This is a rare case of meibomian adenoma in sheep with squamous cell carcinoma coincidence
Pattern densities in fluid dimer models
In this paper, we introduce a family of observables for the dimer model on a
bi-periodic bipartite planar graph, called pattern density fields. We study the
scaling limit of these objects for liquid and gaseous Gibbs measures of the
dimer model, and prove that they converge to a linear combination of a
derivative of the Gaussian massless free field and an independent white noise.Comment: 38 pages, 3 figure
Fluctuations for the Ginzburg-Landau Interface Model on a Bounded Domain
We study the massless field on , where is a bounded domain with smooth boundary, with Hamiltonian
\CH(h) = \sum_{x \sim y} \CV(h(x) - h(y)). The interaction \CV is assumed
to be symmetric and uniformly convex. This is a general model for a
-dimensional effective interface where represents the height. We
take our boundary conditions to be a continuous perturbation of a macroscopic
tilt: for , , and
continuous. We prove that the fluctuations of linear
functionals of about the tilt converge in the limit to a Gaussian free
field on , the standard Gaussian with respect to the weighted Dirichlet
inner product for some explicit . In a subsequent article,
we will employ the tools developed here to resolve a conjecture of Sheffield
that the zero contour lines of are asymptotically described by , a
conformally invariant random curve.Comment: 58 page
Dark energy constraints from quasar observations
Recent measurements of the parameters of the Concordance Cosmology Model
(CDM) done in the low-redshift Universe with Supernovae Ia/Cepheids,
and in the distant Universe done with Cosmic Microwave Background (CMB) imply
different values for the Hubble constant (67.4 0.5 km s Mpc
from Planck vs 74.03 1.42 km s Mpc, Riess et al. 2019).
This Hubble constant tension implies that either the systematic errors are
underestimated, or the CDM does not represent well the observed
expansion of the Universe. Since quasars - active galactic nuclei - can be
observed in the nearby Universe up to redshift z 7.5, they are suitable
to estimate the cosmological properties in a large redshift range. Our group
develops two methods based on the observations of quasars in the late Universe
up to redshift z4.5, with the objective to determine the expansion rate
of the Universe. These methods do not yet provide an independent measurement of
the Hubble constant since they do not have firm absolute calibration but they
allow to test the CDM model, and so far no departures from this model
were found.Comment: 6 pages, 2 figures, contribution to the Proceedings of the 100 years
of the Polish Physical Society Congress, 16-18 October 2020, Warsaw, Poland.
http://info.ifpan.edu.pl/APP
Multiwavelength study of extreme variability in LEDA 1154204: A changing-look event in a type 1.9 Seyfert
Context. Multiwavelength studies of transients in actively accreting
supermassive black holes have revealed that large-amplitude variability is
frequently linked to significant changes in the optical spectra -- a phenomenon
referred to as changing-look AGN (CLAGN).
Aim. In 2020, the Zwicky Transient Facility detected a transient flaring
event in the type-1.9 AGN 6dFGS~gJ042838.8-000040, wherein a sharp increase in
magnitude of 0.55 and 0.3 in the - and -bands, respectively,
occurred over 40 days. Spectrum Roentgen Gamma (SRG)/eROSITA also
observed the object in X-rays as part of its all-sky survey, but only after the
flare had started decaying.
Methods. We performed a three-year, multiwavelength follow-up campaign of the
source to track its spectral and temporal characteristics. This campaign
included multiple ground-based facilities for optical spectroscopic monitoring
and space-based observatories including \textit{XMM-Newton} and \textit{Swift}
for X-ray and UV observations.
Results. An optical spectrum taken immediately after the peak revealed a
changing-look event wherein the source had transitioned from type 1.9 to 1,
with the appearance of a double-peaked broad H line and a blue
continuum, both absent in an archival spectrum from 2005. The X-ray emission
exhibits dramatic flux variation: a factor of 17, but with no spectral
evolution, as the power-law photon index remained 1.9. There is no
evidence of a soft X-ray excess. Overall the object exhibits no apparent
signatures of a tidal disruption event.
Conclusions. The transient event was likely triggered by a disk instability
in a pre-existing accretion flow, culminating in the observed multi-wavelength
variability and CLAGN event.Comment: 34 pages, 24 figures, Submitted to Astronomy & Astrophysic
Wavelength-resolved reverberation mapping of intermediate redshift quasars HE 0413-4031 and HE 0435-4312: Dissecting Mg II, optical Fe II, and UV Fe II emission regions
We present the wavelength-resolved reverberation mapping (RM) of combined
MgII and UV FeII broad-line emissions for two intermediate redshifts
(z1), luminous quasars - HE 0413-4031 and HE 0435-4312, monitored by the
SALT and 1-m class telescopes between 2012-2022. Through this technique, we aim
to disentangle the Mg II and FeII emission regions and to build a
radius-luminosity relation for UV FeII emission, which has so far remained
unconstrained. Several methodologies have been applied to constrain the time
delays for total MgII and FeII emissions. In addition, this technique is
performed to quantify the inflow or outflow of broad-line region gas around the
supermassive black hole and to disentangle the emission/emitting regions from
lines produced in proximity to each other. The mean total FeII time delay is
nearly equal to the mean total Mg II time delay for HE 0435-4312 suggesting a
co-spatiality of their emissions. However, in HE 0413-4031, the mean FeII time
delay is found to be longer than the mean MgII time delay, suggesting that FeII
is produced at longer distances from the black hole. The UV Fe II R-L relation
is updated with these two quasars and compared with the optical FeII relation,
which suggests that the optical FeII region is located further than the UV FeII
by a factor of 1.7-1.9 i.e. . We
detected a weak pattern in the time delay vs. wavelength relation, suggesting
that the MgII broad-line originates a bit closer to the SMBH than the UV FeII,
however, the difference is not very significant. Comparison of MgII, UV, and
optical FeII R-L relations suggests that the difference may be larger for
lower-luminosity sources, possibly with the MgII emission originating further
from the SMBH. In the future, more RM data will be acquired to put better
constraints on these trends, in particular the UV FeII R-L relation.Comment: 24 pages, 16 figures, 5 tables, Accepted for publication in A&A, in
Pres
Wavelength-resolved Reverberation Mapping of quasar CTSC30.10: Dissecting MgII and FeII emission regions
We present the results of the reverberation monitoring aimed at MgII broad
line and FeII pseudocontinuum for the luminous quasar CTS C30.10 (z = 0.90052)
with the Southern African Large Telescope covering the years 2012-2021. We
aimed at disentangling the MgII and UV FeII variability and the first
measurement of UV FeII time delay for a distant quasar. We used several methods
for time-delay measurements and determined both FeII and MgII time delays as
well as performed a wavelength-resolved time delay study for a combination of
MgII and FeII in the 2700 - 2900 \AA restframe wavelength range. We obtain the
time delay for MgII of days in the rest frame, while
for FeII we have two possible solutions of days and
in the rest frame. Combining this result with the old
measurement of FeII UV time delay for NGC 5548 we discuss for the first time
the radius-luminosity relation for UV FeII with the slope consistent with
within uncertainties. Since FeII time delay has a shorter time-delay component
but lines are narrower than MgII, we propose that the line delay measurement is
biased towards the BLR part facing the observer, with the bulk of the Fe II
emission may arise from the more distant BLR region, one that is shielded from
the observer.Comment: 22 pages, 19 Figures, 6 Tables, Submitted to Astronomy and
Astrophysics, Comments are welcom
Thermally Responsive Amphiphilic Conetworks and Gels Based on Poly(N‑isopropylacrylamide) and Polyisobutylene
Novel amphiphilic conetworks (APCN) consisting of thermoresponsive poly(N-isoproplyacrylamide) (PNiPAAm) cross-linked by hydrophobic methacrylate-telechelic polyisobutylene (MA-PIB-MA) were successfully synthesized in a broad composition range. The resulting PNiPAAm-l-PIB conetworks (“l” stands for “linked by”) were obtained by radical copolymerization of NiPAAm with MA-PIB-MA in tetrahydrofuran, a cosolvent for all the components. Low amounts of extractables substantiated efficient network formation. The composition dependent two glass transition temperatures (Tg) by DSC analysis indicate microphase separation of the cross-linked components without mixed phases. It was found that the PNiPAAm-l-PIB conetworks are uniformly swellable in both water and n-hexane; i.e., these new materials behave either as hydrogels or as hydrophobic gels in aqueous or nonpolar media, respectively. The uniform swelling in both polar and nonpolar solutes indicates cocontinuous (bicontinuous) phase morphology. The equilibrium swelling degrees (R) depend on composition, that is, the higher the PIB content, the lower the R in water and the higher in n-hexane. The PNiPAAm phase keeps its thermoresponsive behavior in the conetworks as shown by significant decrease of the swelling degree in water between 20 and 35 °C. The lower critical solubility temperature (LCST) values determined by DSC are found to decrease from 34.1 °C (for the pure PNiPAAm homopolymer) to the range of 25–28 °C in the conetworks, and the extent of the LCST decrease is proportional with the PIB content. Deswelling-swelling, i.e., heating–cooling, cycle indicates insignificant hysteresis in these new thermoresponsive materials. This indicates that PNiPAAm-l-PIB conetworks with predetermined and thermoresponsive swelling behavior can be designed and utilized in several advanced applications on the basis of results obtained in the course of this study
Masonry compressive strength prediction using artificial neural networks
The masonry is not only included among the oldest building materials, but it is also the most widely used material due to its simple construction and low cost compared to the other modern building materials. Nevertheless, there is not yet a robust quantitative method, available in the literature, which can reliably predict its strength, based on the geometrical and mechanical characteristics of its components. This limitation is due to the highly nonlinear relation between the compressive strength of masonry and the geometrical and mechanical properties of the components of the masonry. In this paper, the application of artificial neural networks for predicting the compressive strength of masonry has been investigated. Specifically, back-propagation neural network models have been used for predicting the compressive strength of masonry prism based on experimental data available in the literature. The comparison of the derived results with the experimental findings demonstrates the ability of artificial neural networks to approximate the compressive strength of masonry walls in a reliable and robust manner.- (undefined
The dominant Anopheles vectors of human malaria in the Asia-Pacific region: occurrence data, distribution maps and bionomic précis
<p>Abstract</p> <p>Background</p> <p>The final article in a series of three publications examining the global distribution of 41 dominant vector species (DVS) of malaria is presented here. The first publication examined the DVS from the Americas, with the second covering those species present in Africa, Europe and the Middle East. Here we discuss the 19 DVS of the Asian-Pacific region. This region experiences a high diversity of vector species, many occurring sympatrically, which, combined with the occurrence of a high number of species complexes and suspected species complexes, and behavioural plasticity of many of these major vectors, adds a level of entomological complexity not comparable elsewhere globally. To try and untangle the intricacy of the vectors of this region and to increase the effectiveness of vector control interventions, an understanding of the contemporary distribution of each species, combined with a synthesis of the current knowledge of their behaviour and ecology is needed.</p> <p>Results</p> <p>Expert opinion (EO) range maps, created with the most up-to-date expert knowledge of each DVS distribution, were combined with a contemporary database of occurrence data and a suite of open access, environmental and climatic variables. Using the Boosted Regression Tree (BRT) modelling method, distribution maps of each DVS were produced. The occurrence data were abstracted from the formal, published literature, plus other relevant sources, resulting in the collation of DVS occurrence at 10116 locations across 31 countries, of which 8853 were successfully geo-referenced and 7430 were resolved to spatial areas that could be included in the BRT model. A detailed summary of the information on the bionomics of each species and species complex is also presented.</p> <p>Conclusions</p> <p>This article concludes a project aimed to establish the contemporary global distribution of the DVS of malaria. The three articles produced are intended as a detailed reference for scientists continuing research into the aspects of taxonomy, biology and ecology relevant to species-specific vector control. This research is particularly relevant to help unravel the complicated taxonomic status, ecology and epidemiology of the vectors of the Asia-Pacific region. All the occurrence data, predictive maps and EO-shape files generated during the production of these publications will be made available in the public domain. We hope that this will encourage data sharing to improve future iterations of the distribution maps.</p
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