First-principle Wannier functions and effective lattice fermion models for narrow-band compounds

We propose a systematic procedure for constructing effective lattice fermion models for narrow-band compounds on the basis of first-principles electronic structure calculations. The method is illustrated for the series of transition-metal (TM) oxides: SrVO$_3$, YTiO$_3$, V$_2$O$_3$, and Y$_2$Mo$_2$O$_7$. It consists of three parts, starting from LDA. (i) construction of the kinetic energy Hamiltonian using downfolding method. (ii) solution of an inverse problem and construction of the Wannier functions (WFs) for the given kinetic energy Hamiltonian. (iii) calculation of screened Coulomb interactions in the basis of \textit{auxiliary} WFs, for which the kinetic-energy term is set to be zero. The last step is necessary in order to avoid the double counting of the kinetic-energy term, which is included explicitly into the model. The screened Coulomb interactions are calculated in a hybrid scheme. First, we evaluate the screening caused by the change of occupation numbers and the relaxation of the LMTO basis functions, using the conventional constraint-LDA approach, where all matrix elements of hybridization involving the TM $d$ orbitals are set to be zero. Then, we switch on the hybridization and evaluate the screening associated with the change of this hybridization in RPA. The second channel of screening is very important, and results in a relatively small value of the effective Coulomb interaction for isolated $t_{2g}$ bands. We discuss details of this screening and consider its band-filling dependence, frequency dependence, influence of the lattice distortion, proximity of other bands, and the dimensionality of the model Hamiltonian.Comment: 35 pages, 25 figure

Microwave Lens for Polar Molecules

We here report on the implementation of a microwave lens for neutral polar molecules suitable to focus molecules both in low-field-seeking and in high-field-seeking states. By using the TE_11m modes of a 12 cm long cylindrically symmetric microwave resonator, Stark-decelerated ammonia molecules are transversally confined. We investigate the focusing properties of this microwave lens as a function of the molecules' velocity, the detuning of the microwave frequency from the molecular resonance frequency, and the microwave power. Such a microwave lens can be seen as a first important step towards further microwave devices, such as decelerators and traps.Comment: 4 pages, 3 figure

Estimation of turbulence in fan-rotor wakes for broadband noise prediction during acoustic preliminary design

When calculating broadband fan noise caused by rotor-stator wake interaction analytically, information about the airflow, particularly about the turbulence in the rotor wakes, is necessary. During the pre-design phase, two-dimensional streamline methods are commonly used. These provide only general flow quantities like mean-flow velocities or total-pressure losses. Turbulent parameters such as turbulent kinetic energy and turbulent integral length scale need to be deduced from these quantities. There are several models mentioned in the literature which correlate the wake size with the wake turbulence. But they usually comprise calibration factors that need to be assessed empirically by numerical simulations or measurements. The contribution of the paper is to present an updated semi-empirical model for rotor-wake turbulence quantities, derived on the basis of an extensive comparison of the model with measurements and numerical simulations on four different turbofan stages. A recalibration of the empirical factors improved the noise prediction by 8 dB, reaching an accuracy of 2 dB. In addition, it is shown, that the endwall flow is responsible for large variance in the noise prediction, and may have a contribution of up to 2 dB to the overall sound power

Generalized Fractal Kinetics in Complex Systems (Application to Biophysics and Biothechnology)

We derive a universal function for the kinetics of complex systems. This kinetic function unifies and generalizes previous theoretical attempts to describe what has been called "fractal kinetic".The concentration evolutionary equation is formally similar to the relaxation function obtained in the stochastic theory of relaxation, with two exponents a and n. The first one is due to memory effects and short-range correlations and the second one finds its origin in the long-range correlations and geometrical frustrations which give rise to ageing behavior. These effects can be formally handled by introducing adequate probability distributions for the rate coefficient. We show that the distribution of rate coefficients is the consequence of local variations of the free energy (energy landscape) appearing in the exponent of the Arrhenius formula. We discuss briefly the relation of the (n,a) kinetic formalism with the Tsallis theory of nonextensive systems.Comment: 15 pages, 3 figures, submitted to Physica

Population Structure and Molecular Characterization of Nigerian Field Genebank Collections of Cacao, Theobroma cacao L.

AbstractInadequate knowledge of the population structure and diversity present often hamper the efficient use of germplasm collections. Using a high through-put system, twelve microsatellite loci were used to analyze genetic diversity and population structure in a national field genebank repository of 243 cacao accessions grouped into 11 populations based on their known sources. Based on multi-locus profiles, the Bayesian method was used for individual assignment to verify membership in each population, determine mislabeling and ancestry of some important accessions used in breeding program. A total of 218 alleles was revealed with a mean number of 18.2 alleles per locus. Gene diversity (He= 0.70) and allelic richness (4.34 alleles per locus) were highest in the F1 hybrid population. Differential mating system was suggested as responsible for the observed deficit and excess of heterozygotes observed among the populations. Analysis of molecular variance showed that within-population variance accounted for 63.0% of the total variance while the rest 37% was accounted for by the among-population variance. Cluster dendrogram based on UPGMA revealed two main subsets. The first group was made up of the Amelonado/Trinitario ancestry and the other of Nanay/Parinari ancestry. We found that Nanay and Parinari populations were the major source of Upper Amazon genes utilized while a large proportion of genetic diversity in the field genebank remained under-utilized in development of improved cultivars released to farmers in Nigeria. This study showed that the presence of alleles of the Upper Amazon Forasteros (Nanay, Parinari and Iquitos Mixed Calabacillo) genetic materials in the locally available accessions predated the formal large scale introduction of Upper Amazon materials in 1944. This is the first report of population structure of field genebank collections of cacao in Nigeria since more than seven decades of formal cacao breeding research

A family tree of Markov models in systems biology

Motivated by applications in systems biology, we seek a probabilistic framework based on Markov processes to represent intracellular processes. We review the formal relationships between different stochastic models referred to in the systems biology literature. As part of this review, we present a novel derivation of the differential Chapman-Kolmogorov equation for a general multidimensional Markov process made up of both continuous and jump processes. We start with the definition of a time-derivative for a probability density but place no restrictions on the probability distribution, in particular, we do not assume it to be confined to a region that has a surface (on which the probability is zero). In our derivation, the master equation gives the jump part of the Markov process while the Fokker-Planck equation gives the continuous part. We thereby sketch a {}``family tree'' for stochastic models in systems biology, providing explicit derivations of their formal relationship and clarifying assumptions involved.Comment: 18 pages, 2 figure

Managing weight and glycaemic targets in people with type 2 diabetes—How far have we come?

Introduction: As the vast majority of people with type 2 diabetes (T2D) are also overweight or obese, healthcare professionals (HCP) are faced with the task of addressing both weight management and glucose control. In this narrative review, we aim to identify the challenges of reaching and maintaining body weight targets in people with T2D and highlight current and future treatment interventions. Methods: A search of the PubMed database was conducted using the search terms “diabetes” and “weight loss.”. Results: According to emerging evidence, treating obesity may be antecedent to the development and progression of T2D. While clinical benefits typically set in upon achieving a weight loss of 3–5%, these benefits are progressive leading to further health improvements, and weight loss of >15% can have a disease-modifying effect in people with T2D, an outcome that up to recently could not be achieved with any blood glucose-lowering pharmacotherapy. However, advanced treatment options with weight-loss effects currently in development including the dual GIP/GLP-1 receptor agonists may enable simultaneous achievement of individual glycemic and weight goals. Conclusion: Despite considerable therapeutic progress, there is still a large unmet medical need in patients with T2D who miss their individualized glycemic and weight-loss targets. Nonetheless, it is to be expected that development of future therapies and their use will favourably change the scenario of weight and glucose control in T2D

P33. Expression of alpha v beta 3 integrin in patients with high and low grade glioma

Fuente Fuente, Carlos;Puig-Pey, J.;Buenaño Pastor, Manue

Undetected dysglycaemia common in primary care patients treated for hypertension and/or dyslipidaemia: On the need for a screening strategy in clinical practice. A report from EUROASPIRE IV a registry from the EuroObservational Research Programme of the European Society of Cardiology

Background: Dysglycaemia defined as type 2 diabetes (T2DM) and impaired glucose tolerance (IGT), increases the risk of cardiovascular disease (CVD). The negative impact is more apparent in the presence of hypertension and/or dyslipidaemia. Thus, it seems reasonable to screen for dysglycaemia in patients treated for hypertension and/or dyslipidaemia. A simple screening algorithm would enhance the adoption of such strategy in clinical practice. Objectives: To test the hypotheses (1) that dysglycaemia is common in patients with hypertension and/or dyslipidaemia and (2) that initial screening with the Finnish Diabetes Risk Score (FINDRISC) will decrease the need for laboratory based tests. Methods: 2395 patients (age 18-80 years) without (i) a history of CVD or TDM2, (ii) prescribed blood pressure and/or lipid lowering drugs answered the FINDRISC questionnaire and had an oral glucose tolerance test (OGTT) and HbA1c measured. Results: According to the OGTT 934 (39%) had previously undetected dysglycaemia (T2DM 19%, IGT 20%). Of patients, who according to FINDRISC had a low, moderate or slightly elevated risk 20, 34 and 41% and of those in the high and very high-risk category 49 and 71% had IGT or T2DM respectively. The OGTT identified 92% of patients with T2DM, FPG + HbA1c 90%, FPG 80%, 2hPG 29% and HbA1c 22%. Conclusions: (1) The prevalence of dysglycaemia was high in patients treated for hypertension and/or dyslipidaemia. (2) Due to the high proportion of dysglycaemia in patients with low to moderate FINDRISC risk scores its initial use did not decrease the need for subsequent glucose tests. (3) FPG was the best test for detecting T2DM. Its isolated use is limited by the inability to disclose IGT. A pragmatic strategy, decreasing the demand for an OGTT, would be to screen all patients with FPG followed by OGTT in patients with IFG