Search results for "TF"

Postoperative non-invasive assessment of pulmonary vascular resistance using Doppler echocardiography.

2011

Non-invasive monitoring of pulmonary vascular resistance (PVR) in postoperative cardiac surgery patients might be useful, particularly for management of pulmonary hypertension. For this purpose, we sought to assess Doppler echocardiography in the intensive care setting. In 73 patients, hemodynamics was measured using both, invasive gold standard (pulmonary artery catheter), and non-invasively by Doppler echocardiography. Four Doppler parameters: (1) tricuspid regurgitant velocity/time-velocity-integral of right ventricular outflow tract (TRV/VTI(RVOT)), (2) tricuspid annular systolic velocity (S'), (3) tricuspid annular strain, and (4) tricuspid annular strain rate, were compared with invas…

Dynamics of the scenery flow and geometry of measures

2015

We employ the ergodic theoretic machinery of scenery flows to address classical geometric measure theoretic problems on Euclidean spaces. Our main results include a sharp version of the conical density theorem, which we show to be closely linked to rectifiability. Moreover, we show that the dimension theory of measure-theoretical porosity can be reduced back to its set-theoretic version, that Hausdorff and packing dimensions yield the same maximal dimension for porous and even mean porous measures, and that extremal measures exist and can be chosen to satisfy a generalized notion of self-similarity. These are sharp general formulations of phenomena that had been earlier found to hold in a n…

“ARETE-school” gala ziņojums

2020

Šajā ziņojumā ir informācija par pēcdoktorantūras projektu “Izglītības modernizācija Latvijas skolās, īstenojot inovatīvu pētniecībā balstītu programmu par 21. gadsimta kompetencēm un tikumu ētikas attīstību ar virtuālās telpas atbalstu (ARETE-school)” (Projekta līguma numurs: 1.1.1.2/ VIAA/1/16/071). Projekts tika īstenots no 2017. gada novembra līdz 2020. gada oktobrim, un tā kopējās izmaksas bija EUR 133,806. Projekta iznākuma rādītāji tika pilnībā sasniegti: tika izveidota jauna un ilgtspējīga pētnieka darba vieta, tika publicēti 9 zinātniskie raksti indeksētajos žurnālos un 3 pētniecības ziņojumi, ir izstrādāta jauna tehnoloģija, kura varētu tikt komercializēta (tiešsaistes platforma “…

LU e-resursu repozitorija izmantošana

2020

Carbonatites from the Southern Brazilian platform: I

2020

We present a comprehensive overview of the geochemical characteristics and evolution of the carbonatites from the southern Brazilian Platform (Paraná Basin). The carbonatites from different complexes display large compositional variability in terms of abundances of incompatible and rare earth elements. This is in agreement with an origin from heterogeneous lithospheric sources, as confirmed by isotopic data (see Speziale et al., this issue). The characteristic major and trace element abundances of these carbonatites present compelling evidence for invoking liquid unmixing as the main mechanism of their formation and evolution albeit few exceptions. We propose an evolutionary trend for the B…

Neutrino transport in coherent quasiparticle approximation

2012

We introduce the coherent quasiparticle approximation (cQPA), a model in thermal quantum field theory which describes various effects of temporally varying thermal medium on particle propagation. We present the cQPA Feynman rules and develop related calculational tools. Using these methods we calculate neutrino self energies in the Standard Model and derive an equation of motion for neutrino propagation in a very general framework. Some immediate implications of this equation are discussed. (More detailed abstract in the PDF file.)

Experimental validation of a quaternion-based attitude estimation with direct input to a quadcopter control system

2013

This paper presents a method to calculate the attitude quaternion of a quadcopter with few calculations. The quaternion calculation is based on accelerometers and gyroscopes from an Inertial Measurement Unit (IMU). The quaternion from the accelerometer is calculated as the shortest rotation arc from the gravity vector in the navigation frame. The quaternion from the gyroscope is calculated based on equations of the quaternion derivative. A complementary filter is combining the two quaternions with a componentwise comparison. The attitude estimation is calculated without any trigonometric functions. The quaternion is directly used as an input to the attitude controller. The attitude controll…

A Quasilinear Parabolic Equation with Quadratic Growth of the Gradient modeling Incomplete Financial Markets

2004

We consider a quasilinear parabolic equation with quadratic gradient terms. It arises in the modeling of an optimal portfolio which maximizes the expected utility from terminal wealth in incomplete markets consisting of risky assets and non-tradable state variables. The existence of solutions is shown by extending the monotonicity method of Frehse. Furthermore, we prove the uniqueness of weak solutions under a smallness condition on the derivatives of the covariance matrices with respect to the solution. The in influence of the non-tradable state variables on the optimal value function is illustrated by a numerical example.

Tectono-biosedimentary recordings at the Lias-Dogger transition: example of the Quercy carbonate platform (Aquitaine Basin, France).

2007

AbstractOn the eastern edge of the Aquitaine Basin, the Lias-Dogger transition and the events, which occurred during this time interval are studied in the Quercy sedimentary basin. Stratigraphic correlations are proposed using a biochronological calibration based on the determination of numerous ammonites and brachiopods. Facies analyses using statistical processing integrate the presence of faults and tectonic compartments and lead to reconstruction of palaeoenvironments in space and time. The paper includes the description of system tracts following Haq et al. [1987] and Vail et al. [1991], and twelve palaeogeographic maps of the area studied. The objectives are to distinguish the various…

The Lasting Influences of Early Food-Related Variety Experience: A Longitudinal Study of Vegetable Acceptance from 5 Months to 6 Years in Two Populat…

2016

International audience; Children's vegetable consumption falls below current recommendations, highlighting the need to identify strategies that can successfully promote better acceptance of vegetables. Recently, experimental studies have reported promising interventions that increase acceptance of vegetables. The first, offering infants a high variety of vegetables at weaning, increased acceptance of new foods, including vegetables. The second, offering an initially disliked vegetable at 8 subsequent meals markedly increased acceptance for that vegetable. So far, these effects have been shown to persist for at least several weeks. We now present follow-up data at 15 months, 3 and 6 years ob…