634 research outputs found
Novel calibrations of virial black hole mass estimators in active galaxies based on X-ray luminosity and optical/NIR emission lines
Accurately weigh the masses of SMBH in AGN is currently possible for only a
small group of local and bright broad-line AGN through reverberation mapping
(RM). Statistical demographic studies can be carried out considering the
empirical scaling relation between the size of the BLR and the AGN optical
continuum luminosity. However, there are still biases against low-luminosity or
reddened AGN, in which the rest-frame optical radiation can be severely
absorbed/diluted by the host and the BLR emission lines could be hard to
detect. Our purpose is to widen the applicability of virial-based SE relations
to reliably measure the BH masses also for low-luminosity or intermediate/type
2 AGN that are missed by current methodology. We achieve this goal by
calibrating virial relations based on unbiased quantities: the hard X-ray
luminosities, in the 2-10 keV and 14-195 keV bands, that are less sensitive to
galaxy contamination, and the FWHM of the most important rest-frame NIR and
optical BLR emission lines. We built a sample of RM AGN having both X-ray
luminosity and broad optical/NIR FWHM measurements available in order to
calibrate new virial BH mass estimators. We found that the FWHM of the
H, H and NIR lines (i.e. Pa, Pa and
HeI10830) all correlate each other having negligible or small offsets.
This result allowed us to derive virial BH mass estimators based on either the
2-10 keV or 14-195 keV luminosity. We took also into account the recent
determination of the different virial coefficients for pseudo and classical
bulges. By splitting the sample according to the bulge type and adopting
separate factors we found that our virial relations predict BH masses of
AGN hosted in pseudobulges 0.5 dex smaller than in classical bulges.
Assuming the same average factor for both populations, a difference of
0.2 dex is still found.Comment: 11 pages, 2 figures, 4 tables, accepted for publication on A&
Finite time stability design via feedback linearization
A new nonlinear design technique for Finite-Time Stability for a class of nonlinear systems is developed using feedback linearization. Moreover, a new concept, namely the Finite-Time Contractive Stability with fixed settling time is introduced, giving sufficient conditions for analysis and design. An example illustrates the theoretical results
Insight into the HEV/PHEV optimal control solution based on a new tuning method
The paper presents a formulation of the energy management problem for Hybrid Electrical Vehicles and Plug-in Hybrid Electrical Vehicles alike, which permits to consider different cost indexes like fuel consumption, total and primary energy consumption, economic cost or CO2 footprint. In-depth analysis of the problem optimal solution is done by means of the application of the λ-plot method, which also permits the optimal tuning of other implementable control strategies. Such an approach is used to understand the effect of the selected cost index, the regional energetic share, the driving conditions, and for deriving rules for battery sizing.C. Guardiola and B. Pla research has been partially supported by Ministerio de Ciencia e Innovacion through Project TRA2010-16205 uDiesel, and the Universitat Politecnica de Valencia through Grants PAID-00-11 2105 and PAID-00-11 2106.Guardiola García, C.; Plá Moreno, B.; Onori, S.; Rizzoni, G. (2014). Insight into the HEV/PHEV optimal control solution based on a new tuning method. Control Engineering Practice. 29:247-256. https://doi.org/10.1016/j.conengprac.2014.01.022S2472562
Picosecond Internal Dynamics of Lysozyme as Affected by Thermal Unfolding in Nonaqueous Environment
AbstractA neutron-scattering investigation of the internal picosecond dynamics of lysozyme solvated in glycerol as a function of temperature in the range 200–410K has been undertaken. The inelastic contribution to the measured intensity is characterized by the presence of a bump generally known as “boson peak”, clearly distinguishable at low temperature. When the temperature is increased the quasielastic component of the spectrum becomes more and more intrusive and progressively overwhelms the vibrational bump. This happens especially for T>345K when the protein goes through an unfolding process, which leads to the complete denaturation. The quasielastic term is the superposition of two components whose intensities and linewidths have been studied as a function of temperature. The slower component describes motions with characteristic times of ∼4ps corresponding to reorientations of polypeptide side chains. Both the intensity and linewidth of this kind of relaxations show two distinct regimes with a crossover in the temperature range where the melting process occurs, thus suggesting the presence of a dynamical transition correlated to the protein unfolding. Conversely the faster component might be ascribed to the local dynamics of hydrogen atoms caged by the nearest neighbors with characteristic time of ∼0.3ps
H3 histamine receptor-mediated activation of protein kinase calpha inhibits the growth of cholangiocarcinoma in vitro and in vivo
Histamine regulates functions via four receptors (HRH1, HRH2, HRH3, and HRH4). The D-myo-inositol 1,4,5-trisphosphate (IP(3))/Ca(2+)/protein kinase C (PKC)/mitogen-activated protein kinase pathway regulates cholangiocarcinoma growth. We evaluated the role of HRH3 in the regulation of cholangiocarcinoma growth. Expression of HRH3 in intrahepatic and extrahepatic cell lines, normal cholangiocytes, and human tissue arrays was measured. In Mz-ChA-1 cells stimulated with (R)-(alpha)-(-)-methylhistamine dihydrobromide (RAMH), we measured (a) cell growth, (b) IP(3) and cyclic AMP levels, and (c) phosphorylation of PKC and mitogen-activated protein kinase isoforms. Localization of PKC alpha was visualized by immunofluorescence in cell smears and immunoblotting for PKC alpha in cytosol and membrane fractions. Following knockdown of PKC alpha, Mz-ChA-1 cells were stimulated with RAMH before evaluating cell growth and extracellular signal-regulated kinase (ERK)-1/2 phosphorylation. In vivo experiments were done in BALB/c nude mice. Mice were treated with saline or RAMH for 44 days and tumor volume was measured. Tumors were excised and evaluated for proliferation, apoptosis, and expression of PKC alpha, vascular endothelial growth factor (VEGF)-A, VEGF-C, VEGF receptor 2, and VEGF receptor 3. HRH3 expression was found in all cells. RAMH inhibited the growth of cholangiocarcinoma cells. RAMH increased IP(3) levels and PKC alpha phosphorylation and decreased ERK1/2 phosphorylation. RAMH induced a shift in the localization of PKC alpha expression from the cytosolic domain into the membrane region of Mz-ChA-1 cells. Silencing of PKC alpha prevented RAMH inhibition of Mz-ChA-1 cell growth and ablated RAMH effects on ERK1/2 phosphorylation. In vivo, RAMH decreased tumor growth and expression of VEGF and its receptors; PKC alpha expression was increased. RAMH inhibits cholangiocarcinoma growth by PKC alpha-dependent ERK1/2 dephosphorylation. Modulation of PKC alpha by histamine receptors may be important in regulating cholangiocarcinoma growth. (Mol Cancer Res 2009;7(10):1704-13
MODELLING IN HBIM TO DOCUMENT MATERIALS DECAY BY A THEMATIC MAPPING TO MANAGE THE CULTURAL HERITAGE: THE CASE OF "CHIESA DELLA PIETÀ" IN FERMO
Abstract. Relevant, historically, it is the role of the Diocese of Fermo (Italy) in the Vatican organization dedicated to vast ecclesiastical patrimony on the territory of the Marche region. In this context, for the peculiarity of its identity and its property, the object of this study is the "Chiesa della Pietà". This research starts with the photogrammetric survey to document and analyse the existing condition of the church. The data acquisition provides many scans following a network schema and the photographic survey allows to create orthoimages to make more realistic the 3D representation. Once acquired the geometric and material survey, a series of investigations have been carried out to assess the surface degradation and the material decay of the external façades and internal environments. Furthermore, some structural problems have been occurred, investigating and verifying the presence of advanced stages of deterioration of the wooden structures and the restoration of these structural elements must be mandatory. To take under control the decay and to propose a restoration step, we have arranged the 3D model in HBIM software with different LOD, according to the BIM Forum Level of Development Specification (2016), suitable to develop a well-structured information system. Before the 3D modelling phase, a decomposition of the building is useful to implement a semantic classification of the architectural elements. Basing on a hierarchy of classes and subclasses, the dedicated database organizes the building components assigning an ID-code to the features, putting in evidence materials decay by a thematic mapping.</p
GRB host galaxies with VLT/X-Shooter: properties at 0.8 < z < 1.3
Long gamma-ray bursts (LGRBs) are associated with the death of massive stars.
Their host galaxies therefore represent a unique class of objects tracing star
formation across the observable Universe. Indeed, recently accumulated evidence
shows that GRB hosts do not differ substantially from general population of
galaxies at high (z > 2) redshifts. However, it has been long recognised that
the properties of z < 1.5 hosts, compared to general star-forming population,
are unusual. To better understand the reasons for the supposed difference in
LGRB hosts properties at z < 1.5, we obtained VLT/X- Shooter spectra of six
hosts lying in the redshift range of 0.8 < z < 1.3. Some of these hosts have
been observed before, yet we still lack well constrained information on their
characteristics such as metallicity, dust extinction and star formation rate.
We search for emission lines in the VLT/X-Shooter spectra of the hosts and
measure their fluxes. We perform a detailed analysis, estimating host average
extinction, star-formation rates, metallicities and electron densities where
possible. Measured quantities of our hosts are compared to a larger sample of
previously observed GRB hosts at z < 2. Star-formation rates and metallicities
are measured for all the hosts analyzed in this paper and metallicities are
well determined for 4 hosts. The mass-metallicity relation, the fundamental
metallicity relation and SFRs derived from our hosts occupy similar parameter
space as other host galaxies investigated so-far at the same redshift. We
therefore conclude that GRB hosts in our sample support the found discrepancy
between the properties of low-redshift GRB hosts and the general population of
star- forming galaxies.Comment: 13 pages, 6 figures, accepted for publication in MNRA
The fusion of external and internal 3D photogrammetric models as a tool to investigate the ancient human/cave interaction:The La Sassa case study
Caves have been used by humans and animals for several thousand years until present but, at these time scales, their structures can rapidly change due to erosion and concretion processes. For this reason, the availability of precise 3D models improves the data quality and quantity allowing the reconstruction of their ancient appearance, structure and origin. However, caves are usually characterised by lack of light, high percentage of relative humidity, narrow spaces and complex morphology. Thus, quite often the traditional topographic instruments cannot be employed. In the La Sassa cave (Sonnino, Italy) a huge deposit ranging from Pleistocene to the Second World War has been found and stratigraphic evidence suggested that the shape of the cave and its entrance might have been different. In this paper, the fusion of the internal and external 3D photogrammetric models of the La Sassa, made to support the archaeological excavations, is presented, A Nikon camera with a fisheye lens and a smartphone camera have been used to survey the internal part of the cave, while an aerial drone has been employed for the external area. The two models have been georeferenced and scaled using GCPs acquired by a double frequency GNSS (GPS and GLONASS) receiver. A low-resolution DTM derived from a previous aerial laser scanning survey and the 3D models have been elaborated in CloudCompare environment to highlight the complete morphology of the cave and its surroundings
THE FUSION of EXTERNAL and INTERNAL 3D PHOTOGRAMMETRIC MODELS AS A TOOL to INVESTIGATE the ANCIENT HUMAN/CAVE INTERACTION: The la SASSA CASE STUDY
Caves have been used by humans and animals for several thousand years until present but, at these time scales, their structures can rapidly change due to erosion and concretion processes. For this reason, the availability of precise 3D models improves the data quality and quantity allowing the reconstruction of their ancient appearance, structure and origin. However, caves are usually characterised by lack of light, high percentage of relative humidity, narrow spaces and complex morphology. Thus, quite often the traditional topographic instruments cannot be employed. In the La Sassa cave (Sonnino, Italy) a huge deposit ranging from Pleistocene to the Second World War has been found and stratigraphic evidence suggested that the shape of the cave and its entrance might have been different. In this paper, the fusion of the internal and external 3D photogrammetric models of the La Sassa, made to support the archaeological excavations, is presented, A Nikon camera with a fisheye lens and a smartphone camera have been used to survey the internal part of the cave, while an aerial drone has been employed for the external area. The two models have been georeferenced and scaled using GCPs acquired by a double frequency GNSS (GPS and GLONASS) receiver. A low-resolution DTM derived from a previous aerial laser scanning survey and the 3D models have been elaborated in CloudCompare environment to highlight the complete morphology of the cave and its surroundings
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